In described examples, a first TIR or RTIR element is arranged to introduce at least red light to a first spatial light modulator for modulation thereof, and a second TIR or RTIR element is arranged to introduce at least green light to a second spatial light modulator for modulation thereof. At least one of the first and second TIR or RTIR elements is arranged to introduce blue light to at least one of the first and second spatial light modulators, respectively, for modulation thereof: time-sequentially apart from the first spatial light modulator's modulation of the introduced red light, to an extent the blue light is so introduced to the first spatial light modulator; and time-sequentially apart from the second spatial light modulator's modulation of the introduced green light, to an extent the blue light is so introduced to the second spatial light modulator.