The red-and-blue problem
Red and blue make purple, in theory. In practice, a typical primary red and primary blue give #4C3442, a dark, brownish aubergine. The reason is that most reds contain some yellow, and yellow is purple's complement. A little yellow in the mix pulls it toward brown.
The fix is to choose a red that leans toward blue and a blue that leans toward red:
| Red | Blue | Result |
|---|---|---|
| Primary red | Primary blue | #4C3442, muddy |
| Alizarin crimson | Ultramarine | #4E224E, deep wine |
| Magenta | Ultramarine | #5E2389, clean violet |
| Magenta | Phthalo blue | #45267C, dark blue-violet |
Magenta and ultramarine is the most reliable pair here. If your set has only one red, a crimson or rose works better than a scarlet or cadmium red.
Red-violet or blue-violet
The ratio sets which way the purple leans. With the printing primaries, 1 cyan to 2 magenta gives #65328F, a bright red-violet; equal parts give #5841A6, closer to blue-violet. Adding blue to an existing purple moves it toward indigo, and adding magenta moves it toward fuchsia.
Lavender, lilac and plum
- Lavender and lilac: add white. Magenta, blue and two parts white give #BC89DF. A ready-made purple with four parts white gives a pale #F0DCF6.
- Plum: add a little yellow or a touch of orange to dull the purple. A third of a part of yellow in the magenta and ultramarine mix gives #633565.
- Eggplant: add burnt umber or a little black.
You can try each of these with the tuner under the recipe cards. Because purple pigments are strong, small steps matter, which is why the tuner moves in quarters below one part.
Why purple was once rare
For most of history, purple was the hardest color to obtain. Tyrian purple, made from sea snails, was so expensive that it became the color of emperors. Cheap purple arrived only in 1856, when William Henry Perkin made the first synthetic dye, mauveine. The story is told on our mauve page.
On screen
In RGB, red light plus blue light makes magenta (#FF00FF), and purples are simply blue with some red. That is why digital purple is easy and vivid while paint purple often disappoints. To pick a purple HEX code, see shades of purple or light purple.
Limits of these results
The recipe colors use average student-grade paint values. Real magentas and blues vary a lot between brands, and the model can't account for texture, gloss or how thickly you apply the paint. Use the results to choose a direction, then test on paper.
Five more purples and their recipes
All mixed with the same paint model as the cards above, in parts:
| Shade | Recipe | Result |
|---|---|---|
| Indigo | 3 ultramarine, 1 magenta, ½ black | #393094 |
| Grape | 2 magenta, 2 ultramarine, ½ black | #5C2484 |
| Periwinkle | 2 ultramarine, ½ magenta, 3 white | #AAB1ED |
| Orchid | 2 magenta, ½ ultramarine, 2 white | #E65CC3 |
| Mauve | 1 purple, 1 white, ½ burnt umber | #C18FB7 |
Indigo and periwinkle are both mostly blue; the white alone separates them. Mauve is the odd one: the umber is what turns a pale purple from sweet lilac into the grayed, antique color people mean by mauve.
Purple in watercolor and icing
In watercolor, a purple made from ultramarine settles into tiny grains on rough paper. That speckled texture is a property of the pigment, so don't fight it; if you want a smooth wash, use a phthalo-based blue or a tube violet instead.
Food coloring follows the same rule as paint. Red and blue gels give purple, but many reds lean orange and the result goes gray. A pink or rose gel with a small dot of blue is more dependable. Gel colors also deepen as icing rests, so stop a shade lighter than you want and check again after an hour.
FAQ
What two colors make purple?
Red and blue. For a clean purple, use magenta or crimson with ultramarine.
Why does my purple look brown?
Your red probably leans orange. Switch to a cooler red, or add a little more blue.
What colors make dark purple?
Crimson and ultramarine, or any purple with a touch of burnt umber or black.