You're absolutely right. While I know a few things about light, I only know what exoerts tell me about deer. There was part of one of those articles that said that deer only "detect" green and Blue, and the other one said that they don't have a the third cone required to see red light (as it applies to humans, which is where the extent of my knowledge ends). I tried (and apparently failed) to say in one of my earlier posts that they still may have some relationship with red light, but that my best GUESS is that the response would be the same with a "white" light of the same receptive output. While it seems that they only can tell the difference between Blue and Green (and maybe some combinations therein), red light is still light, and I assume brightens that space without appearing red.
Don't know really. Best guess, going off how humans receive/interpret light.