Hex colors or hexadecimal colors is one way to define colors in html (others are rgb or hsl).
Hex colors are in sixteen steps, from 0 to f (0 is the darkest, f is the lightest) and the basic colors are red, green and blue – 000 is black, fff is white, and 700 is red, 070 is green and 007 is blue in the middle of the range of values – dark to light.
The table below shows the three primary colors – red, green and blue – and three secondary colors – yellow, turquoise and violet – plus shades of gray and a series showing how the changes in the middle color, green, change the hue.
| #300 | #500 | #700 | #800 | #a00 | #c00 | #d00 | #f00 |
| #330 | #440 | #770 | #880 | #aa0 | #cc0 | #dd0 | #ee0 |
| #030 | #050 | #070 | #080 | #0a0 | #0c0 | #0d0 | #0f0 |
| #033 | #044 | #077 | #088 | #0aa | #0cc | #0dd | #0ee |
| #003 | #005 | #007 | #008 | #00a | #00c | #00d | #00f |
| #303 | #404 | #707 | #808 | #a0a | #c0c | #d0d | #e0e |
| #333 | #555 | #666 | #777 | #880 | #aaa | #ccc | #ddd |
| #717 | #737 | #757 | #777 | #797 | #7b7 | #7d7 | #7f7 |
Because they are so easy to edit and make subtle adjustments to, it is better to use hex, rgb or hsl to specify colors rather than color names.