HTML and CSS Reference
In-Depth Information
CSS3 VISUAL EFFECTS
Semi-transparent Color
Aids in: progressive enhancement, e
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ciency
RGBA allows you to specify a color by not only setting the values of red,
green, and blue that it's comprised of, but also the level of opacity it should
have. An alternative to RGBA is HSLA, which works the same way, but
allows you to set values of hue, saturation, and lightness, instead of values
of red, green, and blue. The article Color in Opera 10 — HSL, RGB and Alpha
Transparency explains how HSLA can be more intuitive to use than RGBA.
The 24 Ways web site makes extensive use of RGBA to layer semi-transparent
boxes and text over each other.
