I must admit, I'm not incredibly knowledgable about Predator source material... I've seen both films and I read the comic versions of Concrete Jungle and Cold War, but that's about it. I always wondered about Pred vision, since there isn't much info about it.
If the Predators' real vision is a low-contrast, infrared spectrum (as in the movies,) how could they have possibly developed their civilization the way they did? Meticulous technological construction, differentiating between materials/substances/food sources, recording information in a complicated written language, differentiating between colors and contrasts for the purposes of creating art, etc. would be nearly impossible without the ability to see in the visible spectrum. In the movies and comics, it's at least hinted that Predators ceremonially value different colors, just like tribal human cultures (i.e. black meaning death, red meaning war, gold being an object of wealth, etc.) Should we assume that Predators do have the ability to see beyond infrared without their masks (which would be a total retcon?) How else could their society function?