> What you are probing isn't reasoning, it's perception.

Its both. A colorblind person will admit their shortcomings and, if compelled to be helpful like an LLM is, will reason their way to finding a solution that works around their limitations.

But as LLMs lack a way to reason, you get nonsense instead.

What tools does the LLM have access to that would reveal sub-token characters to it?

This assumes the colorblind person both believes it is true that they are colorblind, in a world where that can be verified, and possesses tools to overcome these limitations.

You have to be much more clever to 'see' an atom before the invention of a microscope, if the tool doesn't exist: most of the time you are SOL.