Hexadecimal color definition

The system of hexadecimal color definition is used in many areas of computer-aided design. In this system, a color is represented by three consecutive hexadecimal numbers , each of which stands for a color in the RGB color space . RGB is an abbreviation for the proportions of the primary colors red , green and blue in the mixed color . The hexadecimal color definition is usually in six-digit form, i.e. as a string of three hexadecimal numbers, each written in two digits, according to the scheme: which allows different states to be defined per octet (= 256) - from 0 for a completely "switched off" color and 255 (FF) for 100% color saturation . This results in ( , therefore ) different colors. It is the additive color mixture used for mixing the colors; the code results in the color yellow because red is mixed with green. #RRGGBB ${\displaystyle 2^{8}}$ ${\displaystyle 2^{8\cdot 3}}$ ${\displaystyle =2^{24}}$ ${\displaystyle 16.777.216}$#FFFF00

This type of notation is often used for web colors for the color design of Internet pages.

Relationship between luminosity and numerical value

Hex value	RGB share	Luminosity (%)
00	0	0%
40	64	25%
80	128	50%
C0	192	75%
FF	255	100%

Examples of color coding

Primary colors colour Hex value R. G B. Complementary to black # 000000 0 0 0 White   Gray # 888888 136 136 136 # 777777     White #FFFFFF 255 255 255 black     red # FF0000 255 0 0 Cyan     Dark red # 880000 136 0 0 # 77FFFF     green # 00FF00 0 255 0 magenta     Dark green # 008800 0 136 0 # FF77FF     blue # 0000FF 0 0 255 yellow     Dark blue # 000088 0 0 136 # FFFF77

Mixed colors of the first degree colour Hex value R. G B. Complementary to Cyan # 00FFFF 0 255 255 red   Dark cyan # 008888 0 136 136 # FF7777     magenta # FF00FF 255 0 255 green     Dark magenta # 880088 136 0 136 # 77FF77     yellow # FFFF00 255 255 0 blue     Dark yellow # 888800 136 136 0 # 7777FF

More mixed colors colour Hex value R. G B. Complementary to Blue green # 00FF88 0 255 136 # FF0077   Sky blue # 0088FF 0 136 255 # FF7700     violet # 8800FF 136 0 255 # 77FF00     Rose # FF0088 255 0 136 # 00FF77     orange # FF8800 255 136 0 # 0077FF     Yellow-green # 88FF00 136 255 0 # 7700FF

Transition red / cyan colour Hex value R. G B. Complementary to Red 14: Cyan 1 # EE1111 238 17th 17th # 11EEEE   Red 4: Cyan 1 # CC3333 204 51 51 # 33CCCC     Red 2: Cyan 1 # AA5555 170 85 85 # 55AAAA     Red 8: Cyan 7 # 887777 136 119 119 # 778888     Red 2: Cyan 3 # 669999 102 153 153 # 996666     Red 4: Cyan 11 # 44BBBB 68 187 187 # BB4444     Red 2: Cyan 13 # 22DDDD 34 221 221 # DD2222

Transition green / magenta colour Hex value R. G B. Complementary to Green 14: Magenta 1 # 11EE11 17th 238 17th # EE11EE   Green 4: Magenta 1 # 33CC33 51 204 51 # CC33CC     Green 2: Magenta 1 # 55AA55 85 170 85 # AA55AA     Green 8: Magenta 7 # 778877 119 136 119 # 887788     Green 2: Magenta 3 # 996699 153 102 153 # 669966     Green 4: Magenta 11 # BB44BB 187 68 187 # 44BB44     Green 2: Magenta 13 # DD22DD 221 34 221 # 22DD22

Transition blue / yellow colour Hex value R. G B. Complementary to Blue 14: Yellow 1 # 1111EE 17th 17th 238 # EEEE11   Blue 4: Yellow 1 # 3333CC 51 51 204 # CCCC33     Blue 2: Yellow 1 # 5555AA 85 85 170 # AAAA55     Blue 8: yellow 7 # 777788 119 119 136 # 888877     Blue 2: yellow 3 # 999966 153 153 102 # 666699     Blue 4: yellow 11 # BBBB44 187 187 68 # 4444BB     Blue 2: yellow 13 # DDDD22 221 221 34 # 2222DD

Other color depths

Hexadecimal color code	Color depth	Number of colors that can be displayed
#RGB	12 bit	2 12 = 4096
#RRGGBB	24 bit	2 24 = 16,777,216
#RRRGGGBBB	36 bit	2 36 = 68,719,476,736
#RRRRGGGGBBBB	48 bit	2 48 = 281,474,976,710,656

In addition to the usual 6-digit color values, 3, 9 and 12-digit color values ​​are also possible. The X Window System supports all four options, even if in practice the 9- and 12-digit color value specifications are reduced to 6-digit ones, as hardly any graphics hardware is able to process such color depths.

Web links

• Hexadecimal color notation in HTML in the SELFHTML Wiki
• Color selector (hexadecimal colors) in SELFHTML
• HTML-color.org - color table with RGB and hex values
• HEX color codes - Comprehensive HEX color code table
• Color table - Color table - Further extensive color code table
• ColorHexa.com - interactive presentation of colors of different coding
• Farben-umrechner.de - Conversion of different color definitions from and to HEX

The colors shown in this article are not binding and may appear different on different display devices.
One possibility to approximately calibrate the display with purely visual means is offered by the adjacent test image (only with native display resolution and when the page is not displayed zoomed):

Set the display device to sRGB mode, if available. If a letter (“R” for red, “G” for green or “B” for blue) appears strongly on one or more of the three gray areas, the gamma correction of the corresponding color channel should be corrected. sRGB corresponds to a gamma value of 2.2, which is the common value for TVs and computers with Windows or macOS (from version 10.6).