Take the lowest color component, and convert that to an alpha value. Then scale the color components by subtracting the lowest, and dividing by the alpha value. Example: 152 converts to an alpha value of (255 – 152) / 255 ~ 0.404 152 scales using (152 – 152) / 0.404 = 0 177 scales using … Read more
The CSS Color Module Level 4 will probably support 4 and 8-digit hexadecimal RGBA notation! Three weeks ago (18th of December 2014) the CSS Color Module Level 4 editor’s draft was submitted to the CSS W3C Working Group. Though in a state which is heavily susceptible to change, the current version of the document implies … Read more
The rgba() function can accept a single hex color as well decimal RGB values. For example, this would work just fine: @mixin background-opacity($color, $opacity: 0.3) { background: $color; /* The Fallback */ background: rgba($color, $opacity); } element { @include background-opacity(#333, 0.5); } If you ever need to break the hex color into RGB components, though, … Read more