What do two primary colours mixed together make?

Answer 1

Any two (of the three) primary colours, when mixed in equal proportions, results in one of the (three) secondary colours.

2 parts red + 2 parts blue = purple

2 parts red + 2 parts yellow = orange

2 parts blue + 2 parts yellow = green

Any two of the primary colours, when mixed in disproportionate amounts, results in one of the (six) tertiary colours.

2 parts red + 1 part blue = red-purple

1 part red + 2 parts blue = blue-purple

2 parts red + 1 part yellow = red-orange

1 part red + 2 parts yellow = yellow-orange

2 parts blue + 1 part yellow = blue-green

1 part blue + 2 parts yellow = yellow-green.