Web (HTML or Hexadecimal) Colors

Colors are specified using a # character to denote the start of the hexadecimal (base 16) color followed by three pairs of hexadecimal digits using the form #RRGGBB where each pair of digits define the amount of red (RR), green (GG) and blue (BB) in a color.

The valid hexadecimal digits are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F where A is 10, B is 11, C is 12, D is 13, E is 14 and F is 15. Any combination of these digits can be used to make the red, green and blue parts of a color. This means that there are 256 combinations (16 digits in the first position x 16 digits in the second position = 256) of each color from 00 to FF inclusive.

Below is a table showing 216 example colors and their hexadecimal notations:

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

NB The above table contains what is known as the "web safe" color palette, it is also known by the following names: browser-safe palette, Netscape palette, 216 color palette, Web palette or 6x6x6 color cube.

Historical note: It's purpose was to provide a consistent palette of colors for a wide variety of browsers and operating systems which at the time usually had 256 colors (8-bit).

The reason that 216 colors were used out of the possible palette of 256 colors is that this allowed an even sampling of color throughout the color space that can be realised on most displays by dividing it up into areas which represent one-sixth of the possible values of all color components of red, green and blue - hence we get a cube which has 6 possible areas of red, 6 of green and 6 of blue which together make up 6x6x6 = 216 combinations.

Today most screens are viewed in True color which uses 24-bits and uses the full range of 256 possible values for each red, green and blue color component which give 256x256x256 = 16777216 colors.

However, this can be quite daunting for non-artists to work with and the web safe palette is a useful starting point when considering color schemes.