An illumination apparatus includes: a red light valve configured to modulate red component light according to a red input signal; a green light valve configured to modulate green component light according to a green input signal; a blue light valve configured to modulate blue component light according to a blue input signal; a fourth color light valve configured to modulate a fourth color component light; and a color combiner configured to combine light emitted from the red light valve, the green light valve and the blue light valve. The fourth color component light emitted from the fourth color light valve enters a certain light valve, which is any one of the red light valve, the green light valve and the blue light valve.