RGB color space

Additive color mixing: adding red to green will yield yellow; adding yellow to blue will yield white.

The RGB color space is an additive color space which models the way light of a few specific frequencies are combined when travelling in the same direction. RGB is known as an additive color space because when light of two different frequencies travel together, from the point of view of an observer, these colors are added to create a new color experience. In particular, the colors which the RGB color space concerns itself with are the red, green and blue frequencies (hence the abbreviation RGB). These three frequencies are chosen because each one corresponds roughly with one of the three types of color-sensitive cones in the human eye. With the appropriate combination of red, green and blue light, one can reproduce many of the colors that can be experienced by a human. For example pure red and green light produce yellow, red and blue make magenta, blue and green equal cyan and red, blue and green generate white.

One common application of the RGB color space to display computer graphics on a monitor. For each pixel in the image, independent values for red, green and blue are stored. There is a fixed range of red, green and blue intensities displayable by the computer monitor, but by choosing the appropriate combination of red, green and blue light, one can stimulate in the human eye the perception of many of the colors between the black level and white point of the monitor being used to display the image. Typically the values stored vary between zero and 255.

As an example:

• (0, 0, 0) is black
• (255, 255, 255) is white
• (255, 0, 0) is red
• (0, 255, 0) is green
• (0, 0, 255) is blue
• (255, 255, 0) is yellow
• (0, 255, 255) is cyan
• (255, 0, 255) is magenta

It is important to note that the intensity of the color output on computer display devices isn't always linear. That is, even though a value of 127 is very close to halfway between zero and 255, the color output of a computer display device when displaying (127, 127, 127) is significantly lower than halfway between the black level[?] and white point[?] of your monitor. This is because most display devices have a gamma characteristic different from 1 (i.e. the behavior of most display devices is, unfortunately, not linear in the relationship between color value and output intensity), and require gamma correction.

In HTML the hexadecimal color coding is used. The table below shows some of the possible colors with their color codes:

000000	000033	000066	000099	0000CC	0000FF
330000	330033	330066	330099	3300CC	3300FF
660000	660033	660066	660099	6600CC	6600FF
990000	990033	990066	990099	9900CC	9900FF
CC0000	CC0033	CC0066	CC0099	CC00CC	CC00FF
FF0000	FF0033	FF0066	FF0099	FF00CC	FF00FF
003300	003333	003366	003399	0033CC	0033FF
333300	333333	333366	333399	3333CC	3333FF
663300	663333	663366	663399	6633CC	6633FF
993300	993333	993366	993399	9933CC	9933FF
CC3300	CC3333	CC3366	CC3399	CC33CC	CC33FF
FF3300	FF3333	FF3366	FF3399	FF33CC	FF33FF
006600	006633	006666	006699	0066CC	0066FF
336600	336633	336666	336699	3366CC	3366FF
666600	666633	666666	666699	6666CC	6666FF
996600	996633	996666	996699	9966CC	9966FF
CC6600	CC6633	CC6666	CC6699	CC66CC	CC66FF
FF6600	FF6633	FF6666	FF6699	FF66CC	FF66FF
009900	009933	009966	009999	0099CC	0099FF
339900	339933	339966	339999	3399CC	3399FF
669900	669933	669966	669999	6699CC	6699FF
999900	999933	999966	999999	9999CC	9999FF
CC9900	CC9933	CC9966	CC9999	CC99CC	CC99FF
FF9900	FF9933	FF9966	FF9999	FF99CC	FF99FF
00CC00	00CC33	00CC66	00CC99	00CCCC	00CCFF
33CC00	33CC33	33CC66	33CC99	33CCCC	33CCFF
66CC00	66CC33	66CC66	66CC99	66CCCC	66CCFF
99CC00	99CC33	99CC66	99CC99	99CCCC	99CCFF
CCCC00	CCCC33	CCCC66	CCCC99	CCCCCC	CCCCFF
FFCC00	FFCC33	FFCC66	FFCC99	FFCCCC	FFCCFF
00FF00	00FF33	00FF66	00FF99	00FFCC	00FFFF
33FF00	33FF33	33FF66	33FF99	33FFCC	33FFFF
66FF00	66FF33	66FF66	66FF99	66FFCC	66FFFF
99FF00	99FF33	99FF66	99FF99	99FFCC	99FFFF
CCFF00	CCFF33	CCFF66	CCFF99	CCFFCC	CCFFFF
FFFF00	FFFF33	FFFF66	FFFF99	FFFFCC	FFFFFF