A Split Complementary Color Scheme is made up of three hues. First you choose your main starting color and select the two colors on either side of its Complementary color.
You can see that no matter where you start, there will always be at least one Tertiary color in your selection. Tertiary colors are blends and will make your resulting palette quite sophisticated with an infinite number of subtle mixtures.
This color scheme is extremely popular with artists and designers.
Here, Violet is selected as the main 'Mother Color'.
On either side of the Yellow directly opposite Violet in the Color Wheel is Yellow/Green and Yellow/Orange. They are shown on the top row. The cleanest, loveliest paint mixtures will be achieved if you mix your own Yellow/Green and Yellow/Orange using the same Yellow for both.
By adding a tiny bit of Violet to the two top paint colors you get some interesting results.
Violet + Yellow/Green = Olive
Violet + Yellow/Orange = Burnt Orange
Violet + Yellow/Green + Yellow/Orange = Neutral Brown
Notice how the 3 mixtures on the bottom row work so well together. There's never any clashing with this method.
Of course you can then alter each of these even further by adding White, Black or Grey. Add more of the three hues too if you begin to lose the color. As long as you stick with the same three and don't add any other Hue, they will always go together.
There are twelve different Split Complementary Color Schemes, one for each of the twelve depending on which is the Mother Color.
Check out these Color Schemes