It would be more straightforward and easier to maintain if SimpleColor were in its now files like ExtenedColor.
Created attachment 400168 [details] Patch
Created attachment 400169 [details] Patch
Created attachment 400170 [details] Patch
Created attachment 400171 [details] Patch
Created attachment 400172 [details] Patch
Committed r262110: <https://trac.webkit.org/changeset/262110> All reviewed patches have been landed. Closing bug and clearing flags on attachment 400172 [details].
<rdar://problem/63581322>