add support for RGB hex colours

[hugowetterberg]

No description provided.

[dannelundqvist]

I think it would be a good idea to support color the two definitions rgb and rgba (e.g. rgb(127, 127, 127,) and rgba(127, 127, 127, 0.5)) to accomodate for different design systems. More and more they are used over hex codes.

[hugowetterberg]

Fair, but I'll limit it to the rgba(255,255,255,1.0) notation, apparently it's possible to use rgba(100%,100%,100%,1.0) .

[hugowetterberg]

During the morning walk I realised that I don't like having the different colour types being top level formats (and mutually exclusive). I'll take another stab at this.

[hugowetterberg]

There's now a colourFormats directive that makes it possible to specify the accepted formats. This makes it possible to accept multiple formats, and it will also be easier to add new colours (like hsl()) in the future.