I just had cataract surgery and received an intraocular lens implant. I must have slowly come to see white as offwhite. My new lens now allows me to see white while my remaining old eye sees white as a bit yellow or brownish, like aged, yellowed paper. We don't all see the world the same. The way the world looks depends upon OUR senses. The sky is blue (in part) because of our senses. Birds, for example, see it differently.