Blue and yellow, but which blue?
Every child learns that blue and yellow make green. What the rhyme leaves out is that the blue decides the green. Blues that lean toward green give clean, bright mixes; blues that lean toward violet give duller, olive ones. Here is the same primary yellow mixed one to one with four different blues:
| Blue | Result | Character |
|---|---|---|
| Cyan | #42C144 | Vivid, almost emerald |
| Phthalo blue | #559E3D | Deep, natural leaf green |
| Primary blue | #639A43 | Mid green |
| Ultramarine | #779941 | Soft and olive |
Ultramarine contains a hint of red, and red is green's complement, so it dulls the mix. If you want bright greens from a two-blue paint set, use the greener one.
Changing the ratio
Yellow is weak and blue is strong, so even a small amount of blue shifts a mix quickly. Start with yellow and add blue to it, not the other way round. With primary blue:
- 1 blue : 1 yellow gives #639A43, a mid leaf green.
- 1 blue : 2 yellow gives #9DB935, a yellow-green near chartreuse.
- 1 blue : 3 yellow gives #B9C52C, close to lime.
A lemon yellow, which leans cool, gives slightly fresher greens than a warm golden yellow.
Olive, sage, mint and forest
- Olive: add a little red, green's complement. Half a part of red in a 1:1 blue and yellow mix gives #73813F. Yellow plus black also makes an olive (#9A9633 at equal parts), which is why black and yellow paint can look green.
- Sage: take an olive and add white plus a touch of gray. See sage green for target shades.
- Mint: cyan, yellow and plenty of white. 1:1:3 gives #99EE9A.
- Forest: phthalo blue and yellow with a little black or burnt umber. Add the dark color very slowly; it takes over fast.
Press Tune this mix on any card and add red, white or black a quarter part at a time to see each change.
A note on tube greens
Ready-made greens such as phthalo green or sap green save time and are often brighter than anything you can mix. Most painters still mix their own landscape greens, because a tube green straight from the tube looks artificial next to real foliage. Warming it with a little yellow ochre or red is the usual fix.
Screen green is different
On a screen, green is a primary of light, and #00FF00 is brighter than any paint. You can't mix it from blue and yellow light: blue plus yellow light makes white or a pale gray, because together they cover the whole spectrum. To pick a green for a website, browse shades of green, or open the color mixer and compare its paint and light results side by side.
How accurate is this?
The swatches come from a pigment-mixing model with fixed sample colors, so they show the direction of a mix rather than an exact match for your brand of paint. Wet acrylic also dries a shade darker. Treat each HEX code as a starting point and check a dried swatch.
Emerald, chartreuse and teal
| Shade | Recipe in parts | Result |
|---|---|---|
| Emerald | 1 phthalo blue, 1 lemon yellow | #57A747 |
| Chartreuse | 3 lemon yellow, ½ cyan | #BEE62D |
| Teal | 2 cyan, 1 green, ¼ black | #00A09F |
The yellow decides a lot here. Lemon yellow leans slightly green already, so it gives cleaner, cooler greens than a warm primary yellow. Chartreuse barely needs any blue at all.
Greens for landscapes
A field painted with one green from the tube looks artificial, because real foliage varies. Two habits make a big difference:
- Vary the yellow, not just the amount of white. Sunlit grass leans yellow, shadowed leaves lean blue. Mixing several greens from the same blue with different yellows keeps them related.
- Push distant trees blue and lighter. Air scatters blue light, so far-off hills lose warmth and contrast. Add a touch of the sky color to greens as they recede.
A little red in a green, as in the olive card above, is also how you get believable olive drab, moss and lichen colors.
FAQ
What two colors make dark green?
Blue and yellow with more blue, or phthalo blue with yellow and a touch of black or burnt umber.
What colors make light green?
Yellow with a little blue, then white. A cyan or phthalo blue gives a fresher light green than ultramarine.
Can you make green without yellow?
Only through another color that contains yellow. Cyan with orange gives #4B9A4B, and 2 cyan to 1 orange gives a sea green, #27A16D. Without yellow somewhere in the mix, there is no green.