RGB

From TrillWiki

RGB stands for "Red Green Blue", and signifies a colo(u)r.

There are 16777216 different colours available using this format.

Common colours are
0,0,0	Black
255,255,255	White
X,X,X	A shade of grey (where X is between 0 and 255)
255,0,255	The magenta commonly used for transparency
255,0,0	Bright red
0,255,0	Bright green
0,0,255	Bright blue

[edit] Trillian notes

Before Trillian supported PNG or GIF transparency in emoticons, transparency was created by using the color RGB: 0,128,128 in your emoticon images.

Trillian also defaults to using magenta, RGB: 255,0,255, as transparent for certain <background>s.

[edit] RGBA

An extension to this is RGBA, or Red Green Blue Alpha. This is the format used by PNG files, in which the last byte, the Alpha channel, is a 0-255 transparency level for each pixel.

[edit] See also

Color space on Wikipedia