allow var functions in style.color values

[ddemolina]

Hi,

I've seen that when I try to insert a value to style.color a function called parseColor not allow to use values with var function like var(--customVar).

One solution is add another regEx in parser.valueType to return a color type but maybe there is a more transversal solution wich is being implementig to support this kind of values in all properties.

Thank you for your help