`green` -> `#008000` `rgba(128, 128, 128, 0.4)` -> `rgba(128, 128, 128, 0.4)` `rgba(128, 128, 128, 0)` -> `rgba(128, 128, 128, 0)` `rgba(128, 128, 128, 1)` -> `#808080` `rgb(128, 128, 128)` -> `#808080`