En HTML les couleurs sont représentées par un nombre hexadécimal formé par six chiffres hexadécimaux (trois paires), précédé d'un pavé, tel que #FFFFFF. Chaque chiffre hexadécimal peut prendre jusqu'à seize valeurs différentes, soit l'ensemble des symboles utilisés 0-9 et A-F.


Chacune des trois paires hexadécimales correspondant aux trois couleurs primaires RGB (rouge, vert et bleu) peut prendre 256 valeurs, allant de 0 à 255 décimales (00 à FF hexadécimal). Ainsi, il y a 16 777 216 combinaisons différentes: 256 x 256 x 256 = 16 777 216

#CCFF00

204, 255, 0

#CCFF33

204, 255, 51

#CCFF66

204, 255, 102

#CCFF99

204, 255, 153

#CCFFCC

204, 255, 204

#CCFFFF

204, 255, 255

#FFFFFF

255, 255, 255

#FFFFCC

255, 255, 204

#FFFF99

255, 255, 153

#FFFF66

255, 255, 102

#FFFF33

255, 255, 51

#FFFF00

255, 255, 0

#CCCC00

204, 204, 0

#CCCC33

204, 204, 51

#CCCC66

204, 204, 102

#CCCC99

204, 204, 153

#CCCCCC

204, 204, 204

#CCCCFF

204, 204, 255

#FFCCFF

255, 204, 255

#FFCCCC

255, 204, 204

#FFCC99

255, 204, 153

#FFCC66

255, 204, 102

#FFCC33

255, 204, 51

#FFCC00

255, 204, 0

#CC9900

204, 153, 0

#CC9933

204, 153, 51

#CC9966

204, 153, 102

#CC9999

204, 153, 153

#CC99CC

204, 153, 204

#CC99FF

204, 153, 255

#FF99FF

255, 153, 255

#FF99CC

255, 153, 204

#FF9999

255, 153, 153

#FF9966

255, 153, 102

#FF9933

255, 153, 51

#FF9900

255, 153, 0

#CC6600

204, 102, 0

#CC6633

204, 102, 51

#CC6666

204, 102, 102

#CC6699

204, 102, 153

#CC66CC

204, 102, 204

#CC66FF

204, 102, 255

#FF66FF

255, 102, 255

#FF66CC

255, 102, 204

#FF6699

255, 102, 153

#FF6666

255, 102, 102

#FF6633

255, 102, 51

#FF6600

255, 102, 0

#CC3300

204, 51, 0

#CC3333

204, 51, 51

#CC3366

204, 51, 102

#CC3399

204, 51, 153

#CC33CC

204, 51, 204

#CC33FF

204, 51, 255

#FF33FF

255, 51, 255

#FF33CC

255, 51, 204

#FF3399

255, 51, 153

#FF3366

255, 51, 102

#FF3333

255, 51, 51

#FF3300

255, 51, 0

#CC0000

204, 0, 0

#CC0033

204, 0, 51

#CC0066

204, 0, 102

#CC0099

204, 0, 153

#CC00CC

204, 0, 204

#CC00FF

204, 0, 255

#FF00FF

255, 0, 255

#FF00CC

255, 0, 204

#FF0099

255, 0, 153

#FF0066

255, 0, 102

#FF0033

255, 0, 51

#FF0000

255, 0, 0

#660000

102, 0, 0

#660033

102, 0, 51

#660066

102, 0, 102

#660099

102, 0, 153

#6600CC

102, 0, 204

#6600FF

102, 0, 255

#9900FF

153, 0, 255

#9900CC

153, 0, 204

#990099

153, 0, 153

#990066

153, 0, 102

#990033

153, 0, 51

#990000

153, 0, 0

#663300

102, 51, 0

#663333

102, 51, 51

#663366

102, 51, 102

#663399

102, 51, 153

#6633CC

102, 51, 204

#6633FF

102, 51, 255

#9933FF

153, 51, 255

#9933CC

153, 51, 204

#993399

153, 51, 153

#993366

153, 51, 102

#993333

153, 51, 51

#993300

153, 51, 0

#666600

102, 102, 0

#666633

102, 102, 51

#666666

102, 102, 102

#666699

102, 102, 153

#6666CC

102, 102, 204

#6666FF

102, 102, 255

#9966FF

153, 102, 255

#9966CC

153, 102, 204

#996699

153, 102, 153

#996666

153, 102, 102

#996633

153, 102, 51

#996600

153, 102, 0

#669900

102, 153, 0

#669933

102, 153, 51

#669966

102, 153, 102

#669999

102, 153, 153

#6699CC

102, 153, 204

#6699FF

102, 153, 255

#9999FF

153, 153, 255

#9999CC

153, 153, 204

#999999

153, 153, 153

#999966

153, 153, 102

#999933

153, 153, 51

#999900

153, 153, 0

#66CC00

102, 204, 0

#66CC33

102, 204, 51

#66CC66

102, 204, 102

#66CC99

102, 204, 153

#66CCCC

102, 204, 204

#66CCFF

102, 204, 255

#99CCFF

153, 204, 255

#99CCCC

153, 204, 204

#99CC99

153, 204, 153

#99CC66

153, 204, 102

#99CC33

153, 204, 51

#99CC00

153, 204, 0

#66FF00

102, 255, 0

#66FF33

102, 255, 51

#66FF66

102, 255, 102

#66FF99

102, 255, 153

#66FFCC

102, 255, 204

#66FFFF

102, 255, 255

#99FFFF

153, 255, 255

#99FFCC

153, 255, 204

#99FF99

153, 255, 153

#99FF66

153, 255, 102

#99FF33

153, 255, 51

#99FF00

153, 255, 0

#00FF00

0, 255, 0

#00FF33

0, 255, 51

#00FF66

0, 255, 102

#00FF99

0, 255, 153

#00FFCC

0, 255, 204

#00FFFF

0, 255, 255

#33FFFF

51, 255, 255

#33FFCC

51, 255, 204

#33FF99

51, 255, 153

#33FF66

51, 255, 102

#33FF33

51, 255, 51

#33FF00

51, 255, 0

#00CC00

0, 204, 0

#00CC33

0, 204, 51

#00CC66

0, 204, 102

#00CC99

0, 204, 153

#00CCCC

0, 204, 204

#00CCFF

0, 204, 255

#33CCFF

51, 204, 255

#33CCCC

51, 204, 204

#33CC99

51, 204, 153

#33CC66

51, 204, 102

#33CC33

51, 204, 51

#33CC00

51, 204, 0

#009900

0, 153, 0

#009933

0, 153, 51

#009966

0, 153, 102

#009999

0, 153, 153

#0099CC

0, 153, 204

#0099FF

0, 153, 255

#3399FF

51, 153, 255

#3399CC

51, 153, 204

#339999

51, 153, 153

#339966

51, 153, 102

#339933

51, 153, 51

#339900

51, 153, 0

#006600

0, 102, 0

#006633

0, 102, 51

#006666

0, 102, 102

#006699

0, 102, 153

#0066CC

0, 102, 204

#0066FF

0, 102, 255

#3366FF

51, 102, 255

#3366CC

51, 102, 204

#336699

51, 102, 153

#336666

51, 102, 102

#336633

51, 102, 51

#336600

51, 102, 0

#003300

0, 51, 0

#003333

0, 51, 51

#003366

0, 51, 102

#003399

0, 51, 153

#0033CC

0, 51, 204

#0033FF

0, 51, 255

#3333FF

51, 51, 255

#3333CC

51, 51, 204

#333399

51, 51, 153

#333366

51, 51, 102

#333333

51, 51, 51

#333300

51, 51, 0

#000000

0, 0, 0

#000033

0, 0, 51

#000066

0, 0, 102

#000099

0, 0, 153

#0000CC

0, 0, 204

#0000FF

0, 0, 255

#3300FF

51, 0, 255

#3300CC

51, 0, 204

#330099

51, 0, 153

#330066

51, 0, 102

#330033

51, 0, 51

#330000

51, 0, 0