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RGB color space

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AdditiveColorMixing.png
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:

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
  

wikipedia.org dumped 2003-03-17 with terodump