Painters have been fighting with colors for centuries. They fought with pigments dug from the earth, with poisonous concoctions made from minerals, with oils, water, and fire. They fought, and they kept losing—until one day, they didn’t. The history of art is, in part, the history of learning how to make red not turn to sludge, how to stop green from looking like sickly pond water, and how to make blue shine without costing the price of a Venetian palace.
The beginner standing at their easel is stepping into that same battlefield. Color mixing looks deceptively simple. Just red and yellow for orange, right? Except what you actually get is a strange brownish smear. What went wrong? Almost always, it’s one of a handful of predictable mistakes. Let’s walk through the five most common, with their fixes, and along the way we’ll see why painters from Titian to van Gogh tripped on the same stones.
1. Buying the Rainbow in Tubes
The first mistake is assuming that every color you want must come premixed in a tube. It’s an understandable error: art shops market paint like candy, rows upon rows of dazzling options. But too many colors on your palette is like inviting everyone you’ve ever met to a dinner party—you won’t get harmony, just noise.
A limited palette forces colors to share parentage. If all your mixes are descended from the same three primaries (plus white and a dark neutral), they automatically relate to each other. Renaissance painters had no choice but to do this; their palettes were tiny compared to ours. Yet that restriction created the rich, unified tones that define the old masters.
The fix: Strip back. Learn your primaries. With a warm and cool version of red, yellow, and blue, you can make almost anything. The point isn’t asceticism. It’s control.
2. Forgetting That Colors Have Bias
Here’s where science ambushes the artist. Pigments are treacherous. Every “pure” red or blue leans one way or another—toward orange or violet, toward green or purple. Pretend they don’t, and you’ll end up with mud.
The problem comes from temperature bias. Take ultramarine blue (a warm, violet-leaning blue) and cadmium yellow (a warm, orange-leaning yellow). Mix them, and instead of a bright green, you get a swampy olive. Why? Because the hidden reds in both pigments canceled out the clarity. Switch cadmium yellow for lemon yellow (a cool, greenish yellow), and suddenly the green comes alive.
The fix: Learn your pigments’ biases. Keep swatch charts. Think of them less as absolutes and more as characters with quirks. Ultramarine is moody. Lemon yellow is sharp and acidic. Put them together with care.
3. Reaching for Black
For centuries, painters reached for lamp black or bone black to make shadows. It worked, but it also killed the life in their colors. Black is a bully: it swallows saturation and spits out lifeless tones. By the nineteenth century, the Impressionists declared war on it. Monet famously refused to keep black on his palette at all. Shadows, he argued, weren’t black. They were blue, or violet, or green, depending on the light.
The fix: Use complements instead. Darken red with green, blue with orange, yellow with purple. The resulting tones are rich, complex, and alive. They echo what our eyes actually perceive, not what we assume shadows should be. Black has its uses—sometimes nothing else will do—but it should be a last resort, not a reflex.
4. Mixing in Isolation
Painters often forget that color never exists alone. A perfect shade on the palette can turn ugly once it lands on the canvas, simply because of the neighbors it finds there. This phenomenon is called simultaneous contrast, first described in 1839 by the chemist Michel Eugène Chevreul. Place two complementary colors side by side, and they intensify each other. Place two near-identical ones together, and one will suddenly look dull.
This is why van Gogh’s yellows blaze against deep blue skies. It’s also why a grey patch can appear warm in one painting and cold in another. Context is everything.
The fix: Test in context. Make swatches on the edge of your canvas. Lay colors next to each other before committing. Don’t trust the palette alone; it lies.
5. Mixing Until It Dies
The final, and perhaps most tragic mistake, is overmixing. You chase a color through layer after layer of additions, trying to nudge it slightly warmer, slightly cooler, slightly lighter. By the end, you have mud.
The science is simple: every pigment subtracts light. The more pigments you add, the more light you lose. The mix tends toward neutral grey or brown. This is why the advice from teachers is always the same: never mix more than two pigments at a time, plus white if necessary. If it’s wrong, start again.
The fix: Restraint. Accept that not every attempt will yield the shade you imagined. Sometimes it’s faster to wipe the palette and begin anew than to rescue a dying color.
Next Reads
- On Shadows: The Science of Shadows: From Caravaggio to Comic Books — why painters kept chasing light, and why shadows are never really black.
- On Color: How to Mix Perfect Greens: Stop Trusting the Tube — the specific rabbit hole that has ruined many palettes, and how to escape it.
- On Perception: Why Hands and Feet Are the Hardest to Draw (and How to Master Them) — another centuries-old artist’s curse, with solutions from anatomy manuals.
- On Art History: The Female Figure in Art: From Classical Ideal to Modern Sketchbook — how one subject has carried the weight of beauty, power, and practice for millennia.
- On Experiments: 10 Simple Pointillism Art Projects for Kids — how van Gogh and Seurat’s color tricks can be turned into playful, hands-on lessons.
Closing
Color mixing is less about recipes and more about relationships—between pigments, between light and shadow, between the eye and the brain. As Jan Matěják puts it in Color Mixing Essentials, color itself doesn’t even exist in the physical world. It’s an illusion, a trick of perception. Painters are illusionists, bending that trick to their will.
The five mistakes above are simply the most common ways that illusion slips out of control. Avoid them, and you inherit centuries of hard-earned knowledge. Fall into them, and you join the long line of artists who cursed at their canvases while trying to make a decent green.