At least 15 percent of human females possess a genetic mutation that gives them an extra (fourth) type of color photoreceptor - and this allows them to discriminate between colors that look identical to the majority of us with a mere three types of color photoreceptors.
David EaglemanKnowing yourself now requires the understanding that the conscious you occupies only a small room in the mansion of the brain, and that it has little control over the reality constructed for you.
David EaglemanWe don't really understand most of what's happening in the cosmos. Is there any afterlife? Who knows.
David Eagleman