Browser Safe Color Palette 

• colors change shade as you move down and up a column.
• moving from right to left, the colors get darker.
• red, green and blue are the main color groups.
• yellow, cyan and magenta neighbor above and below each of the main color groups.

Testing color combinations:

1. Click on any color to set it as the background color,
2. Click on a different color to set is as the text color and
3. a new pop-up window will be displayed using these two colors.  Cool, eh?