Other colors never experienced by ordinary viewing, but perceivable under special artificial laboratory conditions, would also be termed impossible colors.
Perceivable action consequences may vary on two major dimensions: resident vs. remote effects, and cool versus hot outcomes (i.e., reward values associated with action outcomes).
The core assumption of this theory is that actions are coded in terms of the perceivable effects (i.e., the distal perceptual events) they should generate.
In other words, the universe is envisioned as a combination of perceivable material reality and non-perceivable, non-material laws and principles of nature.