Sight occurs when light strikes an object, some colors may be absorbed, and the rest will be reflected towards the viewer. Our retina senses the light waves, and our visual cortex makes sense of it. If I ask you to imagine, however... something different happens.
You can imagine things as they are, or as you understand them, or you can imagine things completely differently.
Imagine a cat, a big, dangerous cat... but imagine it in wonderfully brilliant colors. Imagine it as an otherworldly creature. Make this in your head.
