What are the two colors of light called whose mixture produces white light?

Which two colors of light combine to form the color maroon?

Pigments are mixed by the $......$ method to produce various colors.

Account for the following:
$(a)$ Part of the human eye that helps in changing the focal length of the eye lens.
$(b)$ The condition resulting due to the eye lens becoming cloudy.
$(c)$ The factors on which the colour of the scattered white light depends.
$(d)$ The range of vision of a normal eye.
$(e)$ The sky appears dark to the astronauts in space.

Which of the following colors is not a primary color?

Which of the following colors are primary colors?