CSS RGB Colors

An RGB color value represents RED, GREEN, and BLUE light sources.

RGB Value

In CSS, a color can be specified as an RGB value, using this formula:

rgb(red, greenblue)

Each parameter (red, green, and blue) defines the intensity of the color between 0 and 255.

For example, rgb(255, 0, 0) is displayed as red, because red is set to its highest value (255) and the others are set to 0.

To display black, set all color parameters to 0, like this: rgb(0, 0, 0).

To display white, set all color parameters to 255, like this: rgb(255, 255, 255).

Shades of gray are often defined using equal values for all the 3 light sources:

RGBA Value

RGBA color values are an extension of RGB color values with an alpha channel – which specifies the opacity for a color.

An RGBA color value is specified with:

rgba(red, greenblue, alpha)

The alpha parameter is a number between 0.0 (fully transparent) and 1.0 (not transparent at all):


3D Effect

Portal scene

UI Design