Besides coveryng some basics (color-related terms, like hue, saturation, tone, tint, etc.; additive vs. subtractive color models; etc.), this video covers 6 color categories, that work great in a lot of scenarios:

It’s simple: use 60% of primamry color, 30% of secondary color, and 10% of accent color.

Breaking is not comlex either: add 10% of another accent color (110% total). Or go a- / mono- chromatic.