The way I’ve done it in the past:
- Create 3 lights, and parent them all together.
- Make one fully red, another fully green, and the third fully blue.
- Then create 3 light functions, and pull only the red, green and blue channels from your movie texture accordingly.
- Apply each light function to the corresponding coloured light, and move them into place.
They should add all up correctly to give you your correctly coloured light.
enjoy!