The color of canvas
As an artist with red-green deficiency I struggled for years with painting in oils to obtain the correct colors and hues, often asking others to proof my colors.
I first discovered my 'issue' as a teenager 65 years ago when I was painting a mural on a mirror for friends and they asked why the sky was green. I swore it was gray.
I had begun mixing from primary colors and essentially guessing if I was in the ballpark so to speak. My wife commented that the grass area in one part of a canvas I'm working on was more blue. After putting on the Enchroma glasses I could see her point and corrected it. The change is subtle but even small variations in a painting are extremely pronounced. I need to wear a second pair of glasses for nearness clarity, but I don't find that as troubling as painting in color that is distorted. It was a true gift from my wife and am still trying to find ways to thank her, but that is another long story in itself.