Question To All Physicists

I just watched this video about an Algae Bioreactor (I think it's homemade) at night, and love the "interior lighting" system the guy employs to check the progress of the material culturing (I really know nothing about making algae fuel).

He uses a fluorescent light, which I'm assuming is a typical 2700K (cool/white), and the color of the batches are based on the progress of its culturing.

So lets imagine a 2-lighting system- one light being 2700K so we can verify the progress of the culture, and the other being a custom colored light (or 3-tone LED array). If I understand additive color correctly, could you provide a strong red light to get yellow, or a strong blue light to get cyan? If the light were magenta, would the batch appear white?

Because I want to know, in theory, if you were to assemble a 13,536,000 gallon factory, could you essentially build an iPod Nano screen viewable from space?