The Big Art Lie

Remember: anytime someone argues every color is from Red, Blue and Yellow, they're lying. It's Cyan, Magenta, Yellow, and Black. CMYK is much brighter and more vibrant. You use RBY and all you'll get are dull brown smears. This is probably the biggest lie art teachers will tell young kids.

(This applies to producing physical tones via mixing colors, not digital displays or wavelengths.)