HTML RGB
An RGB color value represents RED, GREEN, and BLUE light sources.
An RGBA color value is an extension of RGB with an Alpha channel (opacity).
In HTML, a color can be specified as an RGB value, using this formula:
rgb(red, green, blue)
Each parameter (red, green, and blue) defines the intensity of the color with a value between 0 and 255.
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).
Color names
Shades of Gray
Shades of gray are often defined using equal values for all three parameters:RGBA Color Values
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, green, blue, alpha)
The alpha parameter is a number between 0.0 (fully transparent) and 1.0 (not transparent at all):
Experiment by mixing the RGBA values below: