Your computer monitor emits light so it stands to reason that the computer uses the three color regions of RED, GREEN, and BLUE (the additive primaries) to reproduce the colors we see.
Working with images destined for the screen or the Web, we designate colors by the amount of RED, GREEN, or BLUE in the color. In your graphics software these numbers might look like this:
- 255 RED 255 GREEN 0 BLUE
- 255R 255G 0B
- RGB: 255,255,0
- FFFF00 (may be written as #FFFF00)
All of these represent yellow. A number between 1-255 designates the amount of each color of red, green, or blue with 255 being the pure 100% value of the color. Zero means none of that color. In order for your computer to understand these numbers we translate them into 6 digit hexidecimal numbers or triplets.
In our example, FF is the hexadecimal equivalent of 255. The hexadecimal triplet is always in the order of RGB so the first FF is red. The second FF is yellow. There is no blue so it has 00, the hexadecimal equivalent of zero.
These are the basics for color on the Web. To delve more deeply into RGB and how color looks on screen, dig into these more detailed resources for Web Color.
Color Basics Index: