Most colour mixers online blend colours the way a screen does, by averaging red, green and blue light. Paint doesn’t work that way. Each pigment absorbs part of the light that hits it and reflects the rest, and when you mix two pigments, both are absorbing at once. What reaches your eye is only the light that neither of them took. That is subtractive mixing, and it’s why the rules you learned from a screen keep failing on the palette.
Three things a screen gets wrong
- Blue and yellow light make grey-white on a screen. Blue and yellow paint make green, because the only light both pigments reflect is the green in between.
- Mixing paint almost always makes it darker and duller, never brighter. Every pigment you add takes more light away. A screen average sits halfway between its colours; a paint mix usually sits below both.
- Strength isn’t equal. One part of Phthalo Blue changes a mix far more than one part of Lemon Yellow. A screen treats every colour the same; paint never does.
Four experiments to try
Each of these takes a minute in the Colour mixer, and each shows something a screen gets wrong.
- Two drops of blue and one of yellow, then a touch of red: watch a bright green turn olive.
- Red and yellow in equal parts, then white: orange, then peach.
- All three primaries with no white: the dark brown painters mix instead of using a tube of black.
- Any colour plus one drop of its opposite on the wheel: the quickest way to knock a colour back.
How this site mixes
Every mix on ColourMixer is computed from each pigment’s reflectance across the visible spectrum, using the Kubelka–Munk model that paint and ink makers use to match colours. Each paint also has a tinting strength, so a speck of Phthalo Blue behaves like a speck of Phthalo Blue. What you see on screen is our best prediction of what the tubes on your table will make.
Mixed from the paints you own
Tell the site which tubes you have and every recipe is solved from those paints, in parts you can measure with a palette knife. If a colour is out of reach of your box, it says so and names the one tube that would get you there. The default is a split-primary set: a warm and a cool version of each primary, plus Titanium White (see The six tubes that mix everything).
Why screen colours can’t always be painted
A screen can show colours no paint can reach, mostly very bright, very saturated ones: electric cyan, neon green, pure screen magenta. When you pull colours from a photo, some of them are simply out of range of real pigment. A paint recipe can only get you to the nearest colour your paints can make, and an honest tool should tell you when that happens rather than pretend.