CSS3 RGB Color

RGB and RGBa

One of two new color models introduced with CSS3, RGB (Red Green Blue) allows you to define any color in the spectrum by mixing the primary colors. For each of the three primary colors, you can specify a value between 0 and 255.

RGBa adds an alpha channel to control the transparency of the color, defined as a value between 0 (transparent) and 1 (opaque).

Colors with RGB