Before you start mixing, it helps to know what you’re aiming for. In most contexts, yellow is a warm, high-lightness colour that sits between orange and green on the colour wheel. But “yellow” from watercolor, acrylic paint, fabric dye, or LED light won’t look identical, because each system creates colour differently.
In paint and other pigments, the colour you see depends on which wavelengths the pigment absorbs and which it reflects. That’s why many “yellow” pigments are slightly greenish (cool yellow) or slightly reddish (warm yellow). Mix a warm yellow with a complementary colour—or add too much of the wrong pigment—and yellow can shift toward orange or even brown.
In light, the story flips. Yellow on a screen is usually created by combining red and green light at the right intensities. That’s why “yellow” on a monitor can look very different from yellow in paint: one is additive colour mixing, the other is subtractive.
