Add parsing color_t (#2015)

Added parsing for color_t:
- #RGB
- #RRGGBB
- rgb(R, G, B)
- hsl(H, S%, L%)
- hsv(H, S%, V%)
- hwb(H, W%, B%)
- cmyk(C%, M%, Y%, K%)
- CSS color names

These are case insensitive and whitespace insensitive. % symbol is also optional.
Limits are checked and throws error if out of range.
Updated doc and added tests