Oh my!

This leap in logic is an excellent example of framing context to synthesize a result.

Humans are all flawed.

In our society, murder is a criminal activity; getting to the truth when one is denying it demands discovering the flaw in one's story. That the murderer happened to be color-blind doesn't alter the fact that they murdered someone. It's not a defense against prosecution.

Isn’t the character flaw that led to the murder the real culprit here. Criticizing using the murderer's color blindness against them is conflating the issue in order to take offense.