Colors in CSS are most often specified by:
- a valid color name – like “red”
- an RGB value – like “rgb(255, 0, 0)”
- a HEX value – like “#ff0000”
Colors set by using color names:
Note: Color names are not case-sensitive: “Red” is the same as “red” or “RED”.
HTML and CSS supports 140 standard color names.
RGB (Red, Green, Blue)
RGB color values can be specified using this formula: rgb(red, green, blue).
Each parameter (red, green, blue) defines the intensity of the color between 0 and 255.
For example, rgb(255,0,0) is displayed as red, because red is set to its highest value (255) and the others are set to 0. Experiment by mixing the RGB values below:
Shades of grey are often defined using equal values for all the 3 light sources:
RGB values can also be specified using hexadecimal color values 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). Note: HEX values are case-insensitive: “#ff0000” is the same as “FF0000”.