Mix blue and yellow paint. You get a dark, murky olive green. Now open any color picker and blend blue and yellow in RGB. Bright green. Cheerful, saturated, completely wrong. This isn't a minor rendering quirk. RGB color mixing is solving a fundamentally different equation than what happens when pigments meet on a surface. After scraping 3,065 reviews across 10 color apps, I found 15 one-star reviews from people explicitly frustrated by fake RGB mixing sold as "paint simulation." One Paleto user put it bluntly: "Another application that is supposed to let you mix paints but does NOT use real world color mixing." I spent a year building an app that does it right, and the rabbit hole went deeper than I expected. What RGB Gets Wrong RGB treats color as three numbers. Convenient for screens, useless for physical reality. A real pigment isn't a point in 3D space. It's a spectral reflectance curve across 380–730nm. Ultramarine blue reflects strongly around 450nm and absorbs nearly everything else.…