Even when switching to SACParserCSS3 in https://github.com/xwiki/xwiki-platform/blob/402653007531cde924e4564c74a13bf27d018ecf/xwiki-platform-core/xwiki-platform-rendering/xwiki-platform-rendering-xwiki/src/main/java/org/xwiki/rendering/internal/wiki/XWikiWikiModel.java#L137, the "Invalid color" error is still raised.
Which is what Antoine Mottier is refering to I guess?