diff --git a/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.cpp b/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.cpp
index b89bd5ff9a2..8588c57c21c 100644
--- a/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.cpp
+++ b/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.cpp
@@ -8,6 +8,7 @@
  */
 
 #include "CSSColorValue.h"
+#include <LibJS/Runtime/AbstractOperations.h>
 #include <LibWeb/CSS/Serialize.h>
 #include <LibWeb/CSS/StyleValues/AngleStyleValue.h>
 #include <LibWeb/CSS/StyleValues/CSSKeywordValue.h>
@@ -33,7 +34,7 @@ Optional<double> CSSColorValue::resolve_hue(CSSStyleValue const& style_value)
 {
     // <number> | <angle> | none
     auto normalized = [](double number) {
-        return fmod(number, 360.0);
+        return JS::modulo(number, 360.0);
     };
 
     if (style_value.is_number())
@@ -146,4 +147,17 @@ void CSSColorValue::serialize_alpha_component(StringBuilder& builder, Serializat
     builder.appendff("{}", resolved_value);
 }
 
+void CSSColorValue::serialize_hue_component(StringBuilder& builder, SerializationMode mode, CSSStyleValue const& component) const
+{
+    if (component.to_keyword() == Keyword::None) {
+        builder.append("none"sv);
+        return;
+    }
+    if (component.is_calculated() && mode == SerializationMode::Normal) {
+        builder.append(component.to_string(mode));
+        return;
+    }
+    builder.appendff("{:.4}", resolve_hue(component).value_or(0));
+}
+
 }
diff --git a/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.h b/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.h
index bb5107d2d1b..24f6733d385 100644
--- a/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.h
+++ b/Libraries/LibWeb/CSS/StyleValues/CSSColorValue.h
@@ -63,6 +63,7 @@ protected:
 
     void serialize_color_component(StringBuilder& builder, SerializationMode mode, CSSStyleValue const& component, float one_hundred_percent_value, Optional<double> clamp_min = {}, Optional<double> clamp_max = {}) const;
     void serialize_alpha_component(StringBuilder& builder, SerializationMode mode, CSSStyleValue const& component) const;
+    void serialize_hue_component(StringBuilder& builder, SerializationMode mode, CSSStyleValue const& component) const;
 
     ColorType m_color_type;
     ColorSyntax m_color_syntax;
diff --git a/Libraries/LibWeb/CSS/StyleValues/CSSLCHLike.cpp b/Libraries/LibWeb/CSS/StyleValues/CSSLCHLike.cpp
index c6ef26fecd9..4a4084322d5 100644
--- a/Libraries/LibWeb/CSS/StyleValues/CSSLCHLike.cpp
+++ b/Libraries/LibWeb/CSS/StyleValues/CSSLCHLike.cpp
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2024, Sam Atkins <sam@ladybird.org>
+ * Copyright (c) 2025, Tim Ledbetter <tim.ledbetter@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -8,6 +9,7 @@
 #include <AK/Math.h>
 #include <AK/TypeCasts.h>
 #include <LibWeb/CSS/Serialize.h>
+#include <LibWeb/CSS/StyleValues/CSSKeywordValue.h>
 #include <LibWeb/CSS/StyleValues/CalculatedStyleValue.h>
 #include <LibWeb/CSS/StyleValues/NumberStyleValue.h>
 #include <LibWeb/CSS/StyleValues/PercentageStyleValue.h>
@@ -36,10 +38,23 @@ Color CSSLCH::to_color(Optional<Layout::NodeWithStyle const&>) const
 }
 
 // https://www.w3.org/TR/css-color-4/#serializing-lab-lch
-String CSSLCH::to_string(SerializationMode) const
+String CSSLCH::to_string(SerializationMode mode) const
 {
-    // FIXME: Do this properly, taking unresolved calculated values into account.
-    return serialize_a_srgb_value(to_color({}));
+    StringBuilder builder;
+    builder.append("lch("sv);
+    serialize_color_component(builder, mode, m_properties.l, 100, 0, 100);
+    builder.append(' ');
+    serialize_color_component(builder, mode, m_properties.c, 150, 0, 230);
+    builder.append(' ');
+    serialize_hue_component(builder, mode, m_properties.h);
+    if ((!m_properties.alpha->is_number() || m_properties.alpha->as_number().number() < 1)
+        && (!m_properties.alpha->is_percentage() || m_properties.alpha->as_percentage().percentage().as_fraction() < 1)) {
+        builder.append(" / "sv);
+        serialize_alpha_component(builder, mode, m_properties.alpha);
+    }
+
+    builder.append(')');
+    return MUST(builder.to_string());
 }
 
 Color CSSOKLCH::to_color(Optional<Layout::NodeWithStyle const&>) const
@@ -53,10 +68,23 @@ Color CSSOKLCH::to_color(Optional<Layout::NodeWithStyle const&>) const
 }
 
 // https://www.w3.org/TR/css-color-4/#serializing-oklab-oklch
-String CSSOKLCH::to_string(SerializationMode) const
+String CSSOKLCH::to_string(SerializationMode mode) const
 {
-    // FIXME: Do this properly, taking unresolved calculated values into account.
-    return serialize_a_srgb_value(to_color({}));
+    StringBuilder builder;
+    builder.append("oklch("sv);
+    serialize_color_component(builder, mode, m_properties.l, 1.0f, 0, 1);
+    builder.append(' ');
+    serialize_color_component(builder, mode, m_properties.c, 0.4f, 0, 2.3);
+    builder.append(' ');
+    serialize_hue_component(builder, mode, m_properties.h);
+    if ((!m_properties.alpha->is_number() || m_properties.alpha->as_number().number() < 1)
+        && (!m_properties.alpha->is_percentage() || m_properties.alpha->as_percentage().percentage().as_fraction() < 1)) {
+        builder.append(" / "sv);
+        serialize_alpha_component(builder, mode, m_properties.alpha);
+    }
+
+    builder.append(')');
+    return MUST(builder.to_string());
 }
 
 }
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-color/parsing/color-valid-lab.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-color/parsing/color-valid-lab.txt
index de59a756bbf..21351be85ad 100644
--- a/Tests/LibWeb/Text/expected/wpt-import/css/css-color/parsing/color-valid-lab.txt
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-color/parsing/color-valid-lab.txt
@@ -2,8 +2,7 @@ Harness status: OK
 
 Found 150 tests
 
-70 Pass
-80 Fail
+150 Pass
 Pass	e.style['color'] = "lab(0 0 0)" should set the property value
 Pass	e.style['color'] = "lab(0 0 0 / 1)" should set the property value
 Pass	e.style['color'] = "lab(0 0 0 / 0.5)" should set the property value
@@ -70,87 +69,87 @@ Pass	e.style['color'] = "oklab(0.5 calc(infinity) 0)" should set the property va
 Pass	e.style['color'] = "oklab(0.5 calc(-infinity) 0)" should set the property value
 Pass	e.style['color'] = "oklab(calc(NaN) 0 0)" should set the property value
 Pass	e.style['color'] = "oklab(calc(0 / 0) 0 0)" should set the property value
-Fail	e.style['color'] = "lch(0 0 0deg)" should set the property value
-Fail	e.style['color'] = "lch(0 0 0deg / 1)" should set the property value
-Fail	e.style['color'] = "lch(0 0 0deg / 0.5)" should set the property value
-Fail	e.style['color'] = "lch(100 230 0deg / 0.5)" should set the property value
-Fail	e.style['color'] = "lch(20 50 20deg/0.5)" should set the property value
-Fail	e.style['color'] = "lch(20 50 20deg/50%)" should set the property value
-Fail	e.style['color'] = "lch(10 20 20deg / -10%)" should set the property value
-Fail	e.style['color'] = "lch(10 20 20deg / 110%)" should set the property value
-Fail	e.style['color'] = "lch(10 20 1.28rad)" should set the property value
-Fail	e.style['color'] = "lch(10 20 380deg)" should set the property value
-Fail	e.style['color'] = "lch(10 20 -340deg)" should set the property value
-Fail	e.style['color'] = "lch(10 20 740deg)" should set the property value
-Fail	e.style['color'] = "lch(10 20 -700deg)" should set the property value
-Fail	e.style['color'] = "lch(-40 0 0)" should set the property value
-Fail	e.style['color'] = "lch(20 -20 0)" should set the property value
-Fail	e.style['color'] = "lch(0 0 0 / 0.5)" should set the property value
-Fail	e.style['color'] = "lch(10 20 20 / 110%)" should set the property value
-Fail	e.style['color'] = "lch(10 20 -700)" should set the property value
-Fail	e.style['color'] = "lch(50% 50% 20)" should set the property value
-Fail	e.style['color'] = "lch(0.5 -20% -20)" should set the property value
-Fail	e.style['color'] = "lch(calc(50 * 3) calc(0.5 - 1) calc(20deg * 2) / calc(-0.5 + 1))" should set the property value
-Fail	e.style['color'] = "lch(calc(-50 * 3) calc(0.5 + 1) calc(-20deg * 2) / calc(-0.5 * 2))" should set the property value
-Fail	e.style['color'] = "lch(calc(50%) 50% 0.5)" should set the property value
-Fail	e.style['color'] = "lch(200 calc(50%) 0.5)" should set the property value
-Fail	e.style['color'] = "lch(-200 calc(50%) 0.5)" should set the property value
-Fail	e.style['color'] = "lch(calc(50%) -100 0.5)" should set the property value
-Fail	e.style['color'] = "lch(none 20 calc(0.5))" should set the property value
-Fail	e.style['color'] = "lch(none none none / none)" should set the property value
-Fail	e.style['color'] = "lch(none none none)" should set the property value
-Fail	e.style['color'] = "lch(20 none none / none)" should set the property value
-Fail	e.style['color'] = "lch(none none none / 0.5)" should set the property value
-Fail	e.style['color'] = "lch(0 0 0 / none)" should set the property value
-Fail	e.style['color'] = "lch(calc(infinity) 0 0)" should set the property value
-Fail	e.style['color'] = "lch(50 calc(infinity) 0)" should set the property value
-Fail	e.style['color'] = "lch(50 calc(-infinity) 0)" should set the property value
-Fail	e.style['color'] = "lch(calc(NaN) 0 0)" should set the property value
-Fail	e.style['color'] = "lch(calc(0 / 0) 0 0)" should set the property value
-Fail	e.style['color'] = "oklch(0 0 0deg)" should set the property value
-Fail	e.style['color'] = "oklch(0 0 0deg / 1)" should set the property value
-Fail	e.style['color'] = "oklch(0 0 0deg / 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(1 2.3 0deg / 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(0.2 0.5 20deg/0.5)" should set the property value
-Fail	e.style['color'] = "oklch(0.2 0.5 20deg/50%)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 20deg / -10%)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 20deg / 110%)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 1.28rad)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 380deg)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 -340deg)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 740deg)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 -700deg)" should set the property value
-Fail	e.style['color'] = "oklch(-4 0 0)" should set the property value
-Fail	e.style['color'] = "oklch(0.2 -0.2 0)" should set the property value
-Fail	e.style['color'] = "oklch(0 0 0 / 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 20 / 110%)" should set the property value
-Fail	e.style['color'] = "oklch(0.1 0.2 -700)" should set the property value
-Fail	e.style['color'] = "oklch(50% 50% 20)" should set the property value
-Fail	e.style['color'] = "oklch(0.5 -20% -20)" should set the property value
-Fail	e.style['color'] = "oklch(calc(0.5 * 3) calc(0.5 - 1) calc(20deg * 2) / calc(-0.5 + 1))" should set the property value
-Fail	e.style['color'] = "oklch(calc(-0.5 * 3) calc(0.5 + 1) calc(-20deg * 2) / calc(-0.5 * 2))" should set the property value
-Fail	e.style['color'] = "oklch(calc(50%) 50% 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(200 calc(50%) 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(-200 calc(50%) 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(calc(50%) -100 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(none 0.2 calc(0.5))" should set the property value
-Fail	e.style['color'] = "oklch(none none none / none)" should set the property value
-Fail	e.style['color'] = "oklch(none none none)" should set the property value
-Fail	e.style['color'] = "oklch(0.2 none none / none)" should set the property value
-Fail	e.style['color'] = "oklch(none none none / 0.5)" should set the property value
-Fail	e.style['color'] = "oklch(0 0 0 / none)" should set the property value
-Fail	e.style['color'] = "lch(20% 80% 10/0.5)" should set the property value
-Fail	e.style['color'] = "oklch(20% 60% 10/0.5)" should set the property value
-Fail	e.style['color'] = "oklch(calc(infinity) 0 0)" should set the property value
-Fail	e.style['color'] = "oklch(0.5 calc(infinity) 0)" should set the property value
-Fail	e.style['color'] = "oklch(0.5 calc(-infinity) 0)" should set the property value
-Fail	e.style['color'] = "oklch(calc(NaN) 0 0)" should set the property value
-Fail	e.style['color'] = "oklch(calc(0 / 0) 0 0)" should set the property value
+Pass	e.style['color'] = "lch(0 0 0deg)" should set the property value
+Pass	e.style['color'] = "lch(0 0 0deg / 1)" should set the property value
+Pass	e.style['color'] = "lch(0 0 0deg / 0.5)" should set the property value
+Pass	e.style['color'] = "lch(100 230 0deg / 0.5)" should set the property value
+Pass	e.style['color'] = "lch(20 50 20deg/0.5)" should set the property value
+Pass	e.style['color'] = "lch(20 50 20deg/50%)" should set the property value
+Pass	e.style['color'] = "lch(10 20 20deg / -10%)" should set the property value
+Pass	e.style['color'] = "lch(10 20 20deg / 110%)" should set the property value
+Pass	e.style['color'] = "lch(10 20 1.28rad)" should set the property value
+Pass	e.style['color'] = "lch(10 20 380deg)" should set the property value
+Pass	e.style['color'] = "lch(10 20 -340deg)" should set the property value
+Pass	e.style['color'] = "lch(10 20 740deg)" should set the property value
+Pass	e.style['color'] = "lch(10 20 -700deg)" should set the property value
+Pass	e.style['color'] = "lch(-40 0 0)" should set the property value
+Pass	e.style['color'] = "lch(20 -20 0)" should set the property value
+Pass	e.style['color'] = "lch(0 0 0 / 0.5)" should set the property value
+Pass	e.style['color'] = "lch(10 20 20 / 110%)" should set the property value
+Pass	e.style['color'] = "lch(10 20 -700)" should set the property value
+Pass	e.style['color'] = "lch(50% 50% 20)" should set the property value
+Pass	e.style['color'] = "lch(0.5 -20% -20)" should set the property value
+Pass	e.style['color'] = "lch(calc(50 * 3) calc(0.5 - 1) calc(20deg * 2) / calc(-0.5 + 1))" should set the property value
+Pass	e.style['color'] = "lch(calc(-50 * 3) calc(0.5 + 1) calc(-20deg * 2) / calc(-0.5 * 2))" should set the property value
+Pass	e.style['color'] = "lch(calc(50%) 50% 0.5)" should set the property value
+Pass	e.style['color'] = "lch(200 calc(50%) 0.5)" should set the property value
+Pass	e.style['color'] = "lch(-200 calc(50%) 0.5)" should set the property value
+Pass	e.style['color'] = "lch(calc(50%) -100 0.5)" should set the property value
+Pass	e.style['color'] = "lch(none 20 calc(0.5))" should set the property value
+Pass	e.style['color'] = "lch(none none none / none)" should set the property value
+Pass	e.style['color'] = "lch(none none none)" should set the property value
+Pass	e.style['color'] = "lch(20 none none / none)" should set the property value
+Pass	e.style['color'] = "lch(none none none / 0.5)" should set the property value
+Pass	e.style['color'] = "lch(0 0 0 / none)" should set the property value
+Pass	e.style['color'] = "lch(calc(infinity) 0 0)" should set the property value
+Pass	e.style['color'] = "lch(50 calc(infinity) 0)" should set the property value
+Pass	e.style['color'] = "lch(50 calc(-infinity) 0)" should set the property value
+Pass	e.style['color'] = "lch(calc(NaN) 0 0)" should set the property value
+Pass	e.style['color'] = "lch(calc(0 / 0) 0 0)" should set the property value
+Pass	e.style['color'] = "oklch(0 0 0deg)" should set the property value
+Pass	e.style['color'] = "oklch(0 0 0deg / 1)" should set the property value
+Pass	e.style['color'] = "oklch(0 0 0deg / 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(1 2.3 0deg / 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(0.2 0.5 20deg/0.5)" should set the property value
+Pass	e.style['color'] = "oklch(0.2 0.5 20deg/50%)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 20deg / -10%)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 20deg / 110%)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 1.28rad)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 380deg)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 -340deg)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 740deg)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 -700deg)" should set the property value
+Pass	e.style['color'] = "oklch(-4 0 0)" should set the property value
+Pass	e.style['color'] = "oklch(0.2 -0.2 0)" should set the property value
+Pass	e.style['color'] = "oklch(0 0 0 / 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 20 / 110%)" should set the property value
+Pass	e.style['color'] = "oklch(0.1 0.2 -700)" should set the property value
+Pass	e.style['color'] = "oklch(50% 50% 20)" should set the property value
+Pass	e.style['color'] = "oklch(0.5 -20% -20)" should set the property value
+Pass	e.style['color'] = "oklch(calc(0.5 * 3) calc(0.5 - 1) calc(20deg * 2) / calc(-0.5 + 1))" should set the property value
+Pass	e.style['color'] = "oklch(calc(-0.5 * 3) calc(0.5 + 1) calc(-20deg * 2) / calc(-0.5 * 2))" should set the property value
+Pass	e.style['color'] = "oklch(calc(50%) 50% 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(200 calc(50%) 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(-200 calc(50%) 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(calc(50%) -100 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(none 0.2 calc(0.5))" should set the property value
+Pass	e.style['color'] = "oklch(none none none / none)" should set the property value
+Pass	e.style['color'] = "oklch(none none none)" should set the property value
+Pass	e.style['color'] = "oklch(0.2 none none / none)" should set the property value
+Pass	e.style['color'] = "oklch(none none none / 0.5)" should set the property value
+Pass	e.style['color'] = "oklch(0 0 0 / none)" should set the property value
+Pass	e.style['color'] = "lch(20% 80% 10/0.5)" should set the property value
+Pass	e.style['color'] = "oklch(20% 60% 10/0.5)" should set the property value
+Pass	e.style['color'] = "oklch(calc(infinity) 0 0)" should set the property value
+Pass	e.style['color'] = "oklch(0.5 calc(infinity) 0)" should set the property value
+Pass	e.style['color'] = "oklch(0.5 calc(-infinity) 0)" should set the property value
+Pass	e.style['color'] = "oklch(calc(NaN) 0 0)" should set the property value
+Pass	e.style['color'] = "oklch(calc(0 / 0) 0 0)" should set the property value
 Pass	e.style['color'] = "lab(calc(50 + (sign(1em - 10px) * 10)) 30 50 / 50%)" should set the property value
 Pass	e.style['color'] = "oklab(calc(0.5 + (sign(1em - 10px) * 0.1)) 0.3 0.5 / 50%)" should set the property value
 Pass	e.style['color'] = "lab(60 30 50 / calc(50% + (sign(1em - 10px) * 10%)))" should set the property value
 Pass	e.style['color'] = "oklab(0.6 0.3 0.5 / calc(50% + (sign(1em - 10px) * 10%)))" should set the property value
-Fail	e.style['color'] = "lch(calc(50 + (sign(1em - 10px) * 10)) 30 50deg / 50%)" should set the property value
-Fail	e.style['color'] = "oklch(calc(0.5 + (sign(1em - 10px) * 0.1)) 0.3 50deg / 50%)" should set the property value
-Fail	e.style['color'] = "lch(60 30 50deg / calc(50% + (sign(1em - 10px) * 10%)))" should set the property value
-Fail	e.style['color'] = "oklch(0.6 0.3 50deg / calc(50% + (sign(1em - 10px) * 10%)))" should set the property value
\ No newline at end of file
+Pass	e.style['color'] = "lch(calc(50 + (sign(1em - 10px) * 10)) 30 50deg / 50%)" should set the property value
+Pass	e.style['color'] = "oklch(calc(0.5 + (sign(1em - 10px) * 0.1)) 0.3 50deg / 50%)" should set the property value
+Pass	e.style['color'] = "lch(60 30 50deg / calc(50% + (sign(1em - 10px) * 10%)))" should set the property value
+Pass	e.style['color'] = "oklch(0.6 0.3 50deg / calc(50% + (sign(1em - 10px) * 10%)))" should set the property value
\ No newline at end of file