In HTML, a color can also be specified using a hexadecimal value in the form: #RRGGBB, where RR (red), GG (green) and BB (blue) are hexadecimal values between 00 and FF (same as decimal 0-255).
For example, #FF0000 is displayed as red, because red is set to its highest value (FF) and the others are set to the lowest value (00).
Example
| Color | HEX |
|---|---|
| #FF0000 | |
| #FFFF00 | |
| #00FF00 | |
| #00FFFF | |
| #0000FF |
Shades of gray are often defined using equal values for all the 3 light sources:
Example
| Color | HEX |
|---|---|
| #000000 | |
| #404040 | |
| #808080 | |
| #CCCCCC | |
| #FFFFFF |

