Idea: Using wikimedia/css-sanitizer to validate color

[lens0021]

\PortableInfobox\Helpers\InfoboxParamsValidator::validateColorValue() validates CSS Color Module Level 3 (or 4, I am not sure which) and wikimedia/css-sanitizer is a package for Extension:TemplateStyles and \Wikimedia\CSS\Grammar\MatcherFactory::color() seems to be matches colors.

I think implementing and maintaining the validation of CSS Color 3 in this extension is overdoing. So we should consider using an external library.

But there are a few problems, for example, css-sanitizer doesn't know about #rrggbbaa (T265675 RGBA hexadecimal value is not supported in background-color (no support for transparency value)). In fact, the regular expression that this extension uses is more detailed and accepts usual values. This is why I think this is an idea.