With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: In cerebral achromatopsia, a person sees only in black and white even though the eyes are capable of distinguishing colors. Some sources do not consider these to be true color blindness, because the failure is of perception, not of vision. They are forms of visual agnosia.
text_B: Would a pathologist examining a deceased person's eye tissue be able to determine that they had a defect of color vision?
NO.