colors

Traditional model: 

Primary: red, blue, yellow

Secondary: 

red+blue = purple

red+yellow = orange

blue+yellow = green

Tertiary(Third): secondary + primary

Additive model:

Primary: rgb

Secondary:

r/g - y(yellow)

r/b - m(magenta)

g/b - c(cyan) 

*black: r = 0, g = 0, b = 0