Sass/Compass - Convert Hex, RGB, or Named Color to RGBA

Question

This may be Compass 101, but has anyone written a mixin which sets the alpha value of a color? Ideally, I would like the mixin to take any form of color definition, and apply transparency:

@include set-alpha( red, 0.5 );          //prints rgba(255, 0, 0, 0.5); @include set-alpha( #ff0000, 0.5 );      //prints rgba(255, 0, 0, 0.5); @include set-alpha( rgb(255,0,0), 0.5 ); //prints rgba(255, 0, 0, 0.5); 

Answer 1

Use the rgba function built into Sass

Sets the opacity of a color.

Examples:

rgba(#102030, 0.5) => rgba(16, 32, 48, 0.5)
rgba(blue, 0.2) => rgba(0, 0, 255, 0.2)

Parameters:
(Color) color
(Number) alpha — A number between 0 and 1

Returns:
(Color)

Code:

rgba(#ff0000, 0.5); // Output is rgba(255,0,0,0.5); 

Answer 2

The rgba function doesn't work on color with no transparency, it returns an hex again. After all, it's not meant to transform hex to rgba, we're just making profit out of hex doesn't allow alpha (yet).

rgba(#fff, 1) // returns #fff 

So, I made al little functions that buils the rgb string. I don't need to deal with transparencies for now.

@function toRGB ($color) {     @return "rgb(" + red($color) + ", " + green($color) + ", " + blue($color)+ ")"; }