Red colour is something which has sort of become a canonical example of subjective experience. Nothing special about it - could have been blue :)
Without the ability to communicate, consciousness means nothing at all. Then of course communicate how? Hand signals, hand writing or voice are equally mystical forms of communication given that these are waves(light and sound). That's already Telepathy category. We just don't feel it as magical because every one can do it.
I'd imagine for a humanoid species without ears or even a idea that something like sound wave would exist, talking would be synonymous with Telepathy.
Communication is the only data you have to support the theory that there are conscious beings other than yourself. Hypothesizing a conscious being that can't communicate at all (not to be confused with the temporary inability to communicate brought on by sleep or locked-in syndrome) is like hypothesizing an invisible leprechaun living in your pantry.
Agency is not a binary quantity. A normal adult human is an agent, and a blastocyst is not, but there is no bright line where agency is bestowed. It happens gradually.
None of this is a deep mystery. The only thing that is mysterious is how the transition happens. But panpsychism is just absurd.
Just out of curiosity, why did you pick "red color" as your canonical example of subjective experience? The reason I ask is that it seems to pop up much more often than random chance would predict.