I’ve been irritated for years by Analytic philosophers saying that they see redness (the claim probably came from all the discussions of “qualia”, but it spills over into other things). This is obviously false: you see this particular red surface of / radiation of ____. One no more sees redness than he sees humanity, and for the same reason.
There is some sense in which one sees redness, to be sure, but in order to profit from saying this it needs to be recognized as not per se what your eyeballs are aware of. The observation isn’t trivial: one of the most fertile problems that the ancients worked with was the fact that we somehow see man (or redness) even while we only see this man; we hear sound even while we only hear this sound. On the one hand, there are pretty obvious differences between sound and this sound (since this sound ceasing doesn’t make the whole universe go silent) on the other hand there are obvious identities between sound and this one (for what sound could exist without being, in fact, this one?) Plato was forced to posit an entire second universe and a previous and eternal life in order to deal with this problem; Aristotle wrote one of the longest books in his corpus (Metaphysics VII) while struggling with the strange unity and distinction of “this X” (the “hoc aliquid” or “tode ti”) and “X-ness”. There is an inescapable ambiguity in even the word “red”: do you mean this one, or what is common to this one and that (this is the opposition between the tode ti or hoc aliquid and the quod quid erat esse or essence). This is an extremely difficult, fundamental, and illuminating problem, which one skates right past if he doesn’t reflect on how he doesn’t see redness.