Basically the same reason you can’t imagine a new number – by defining what it is you already sort of categorised every possible one as known.
What our brain understands as color has a finite range of possibilities – whatever combination of signals our eyes can send. If something can be made of those signals its an existing color. It could be a color with interesting properties (like number pi) or one noone ever really thought about before (maybe due to being weirdly specific like 5.412786437906435743), but because it is a color its not a new one.
Latest Answers