[External] : Alpha colors derivation from color constants in CSS

[Nir Lisker]

Hi,

JavaFX has no way to derive rgba colors from color constants, but it can
derive brightness changes. For example:

.root {
    -primary: #d4af37; // rgb:  212, 175, 55
    -dim: derive(-primary, -25%); // brightness change
    -wash: rgba(212, 175, 55, 0.14); // works by retyping the numbers
    -wash2: rgba(-primary, 0.25); // fails: Expected '<number>' or
'<percentage>' while parsing '-wash2'
}

I haven't done much work in the CSS parser area. Can this functionality be
implemented in a CSS spec-compliant way?

- Nir