This is something I've been thinking of for a while... I'm just gonna post it: What we perceive as "color" is the frequency of photon waves hitting our retina (the back of your eyeball lined with cones and rods). The method it sends electrical signals to the brain is based on timing: high frequencies are blue, low frequencies are red. Our pupils are black because they are absorbing all waves within the visual spectrum; black is the only color reflected back because black is coded for whatever's outside our visual range. The pfhor don't have human eyes, but the fact we see them as red tells us something: the surface of their eyes reflect waves in the red-to-infrared frequencies. They may see into ultraviolet, but that's speculative. What is fact is that they don't see red frequency waves because they are not hitting their retinas.
The terminals in all the pfhor ships are in red text. They can't read it.
But that's silly. There is another logical conclusion: the red text is a high amplitude wave that includes infrared waves we can't see, or a combined wave that includes UV waves. I think the former is more probable... except that's weird. It means they have a blind spot in the middle of their visual spectrum. If their eyes reflect red, they HAVE to be absorbing the green and blue waves above that frquency. If they saw infrared as well, that's like... remember how I said Blue is high and Red is low in our spectrum? Green is in the middle. Imagine us having green pupils and not seeing green.
The red text could be a red frequency that is higher than the red frequency their eyes reflect. And they gave the s'pht those red cloaks!