Rainbow Color Selector
This is a traditional wheel using primary, secondary, complimentary, tertiary tiers, split-compliment, rectangular and square tetrad, analogous and monochromatic for combining and contrasting colors to get the best look.
The very detailed instructions include how to successfully use the Color Selector, basic color theory to help you understand what you're seeing, and why various colors and hues match, contrast or simply don't work together.
Easy enough for beginners, and comprehensive enough for advanced users.
Instruction leaflet enclosed.