Colour within brands e.g. Coke Cola red. You have associations learnt associations with the colour and that is due to semiotics. These can be different between cultures. Colour choice is important.
ROY GBIV = the colours of the rainbow
HUE → the colour itself
SATURATION → How intense the colour is. Washed out or deep?
LIGHTNESS → How much white or black it has in the mix.
CMYK → Cyan, Magenta, Yellow, Key (Black). This is used for printing and in that order because black is the heaviest.
RGB → Red, Green, Blue. This is used for projection / light. 100% RGB = White because the more you project the lighter it gets.
PRIMARY COLOURS → Red, Blue, Yellow.
SECONDARY COLOURS → Green, Purple, Orange.
TERTIARY COLOURS → Dark blue, Cyan, Magenta, etc.
MONOCHROMATIC COLOURS → One colour with saturation and lightness adjusted to keep it consistent.
ANALOGOUS COLOURS → Associated in close proximity. Not the same colours but close on the colour wheel.
CLASHING COLOURS → Colours with no relation on the colour wheel.
COMPLEMENTARY COLOURS → Opposite colours on the colour wheel. These work well with each other and most likely have the same saturation.
SPLIT COMPLIMENTARY → Three complimentary all the same saturations. Using two would look like they clash.
NEUTAL COLOURS → Same colour group two tones from the same section. Dark colour doesn’t have to be the shadow within branding.