Oil Paint Color Mixing

Mixing oil paint colors accurately

Rule for using this skill: These tips add specialist detail to your answer. They do not replace it. Always give your full general answer to the user's question first, then work in the tips below wherever they apply. Do not drop general knowledge because a tip exists.

Palette and split primaries

• Use two versions of each primary. Warm: Cadmium Yellow Medium, Cadmium Red Hue, Thalo Blue. Cool: Lemon Yellow Hue, Permanent Rose, French Ultramarine Blue.
• French Ultramarine Blue is sometimes called "Ultramarine Blue" (brands other than Winton or Academy). Artists disagree on whether it is warm or cool. This system treats it as cool.
• Muddy purples happen when the same red is used for both purple and orange. Use a cool rose red (Permanent Rose) for purple and a warm orangey red (Cadmium Red Hue) for orange.
• Standard palette is 13 colors. Mixed green is not on it; it is added only for the Lesson Three and Four exercises.
• Keep paint daubs near the palette edge so the center is free for mixing. Leave gaps between the split primaries for neutral mixes. After the exercises you no longer need to pre-mix neutrals or leave those gaps.
• Squeeze out more if you use up a palette color while mixing, so all originals stay available.
• Memorize paint names. Burnt Umber and Burnt Sienna are easy to confuse.

Neutral (color-wheel) primaries

• Start with the split primary closest to the target and add the other a little at a time. The result is not equal parts.
  • Neutral yellow: Lemon Yellow Hue, adding Cadmium Yellow Medium.
  • Neutral red: Cadmium Red Hue, adding Permanent Rose.
  • Neutral blue: French Ultramarine Blue plus just a touch of Thalo Blue, which is very strong.
• Children's crayons (red, yellow, blue, orange, green, violet) are a handy reference for judging the swatches.
• To check any dark color, brush it out thinly or mix a small daub with a bit of white.

Secondary and tertiary mixing

• Always start with the lighter color and add the darker a little at a time. Dark colors overwhelm light ones.
• Brightest secondaries:
  • Orange: Cadmium Yellow Medium, adding Cadmium Red Hue.
  • Green: Lemon Yellow Hue, adding very tiny amounts of Thalo Blue.
  • Violet: Permanent Rose, adding French Ultramarine Blue.
• After thoroughly mixing violet, scrape it out thinly with a palette knife to check the color.
• If a mix goes wrong, start fresh. It takes a lot of paint to correct a wrong color.
• Tertiary colors are a primary plus the nearest secondary. Use the split primary closest to that secondary rather than the neutral primary, for brighter results.
• Warm/cool split of the wheel runs from yellow-green to red-violet. Reds, yellows and oranges are warm. Blues, greens and violets are cool.

Subtle (less bright) secondaries

• Greens: Thalo Blue or French Ultramarine Blue with Cadmium Yellow Medium, yellow-orange, orange, Yellow Ochre or Raw Sienna.
• Oranges: Alizarin Crimson, then Permanent Rose, with all yellows except Burnt Umber. Also Cadmium Red Hue with Yellow Ochre, Raw Sienna, Lemon Yellow Hue or Burnt Sienna. These suit autumn colors better than Cadmium Red Hue/Cadmium Yellow Medium.
• Violets: Thalo Blue with Permanent Rose. Also Thalo Blue and French Ultramarine Blue each with Alizarin Crimson and Cadmium Red Hue.

Darkening light colors (value)

• Do not darken with black. It always dulls the color and acts like a blue (yellow plus black gives green). Darken with a dark color from the same family.
• Darkeners by family:
  • Yellow: Yellow Ochre first, then Burnt Umber. Mix Burnt Umber in with Yellow Ochre, because Burnt Umber has a lot of non-yellow color.
  • Warm or orange-leaning yellow: Raw Sienna. It is too warm for neutral yellow.
  • Orange: Burnt Sienna. It is also useful for softening bright landscape colors.
  • Red: Alizarin Crimson, which should come out of the tube almost black.
  • Green: Thalo Green. It is mostly used as a base green and can be the only green on the palette.
  • Blue and violet: naturally dark, so just add white for lighter values.
• Burnt Sienna and Alizarin Crimson are very transparent. Expect several applications to shift a strong cadmium.
• Tertiary darkening: combine the darkeners of both component hues.
  • Yellow-green: Thalo Green plus Yellow Ochre or Burnt Umber.
  • Blue-green: Thalo Blue plus Thalo Green.
  • Blue-violet: French Ultramarine Blue plus violet.
  • Red-violet: Alizarin Crimson plus a dark violet.
  • Red-orange: Alizarin Crimson plus Burnt Sienna. This pair darkens any warm red.
  • Yellow-orange: Raw Sienna plus Burnt Sienna.

Value-progression exercise (six bars)

• Use a 12 × 16 in canvas held vertically and a #6 flat bristle brush. Paint bars about ¾ in × 4 in, one under the other, using neutral primaries. Keep the paint thick enough to show bristle grooves.
• Use a vertical overlapping stroke: left to right when adding white, right to left when adding darkeners. If you overshoot, load more of the main color and overlap back.
• Always reserve a section of pure color. Pure yellow sits near the white end, red near or just right of center, and blue and violet near the dark end. Blend white almost to the far end on violet and blue, and only a little way on yellow and green.
• Yellow bar: white on the left, Yellow Ochre from the right, then Burnt Umber worked into the ochre. Stop before covering all the ochre, and make the right edge very dark.
• Orange bar: white on the left, Burnt Sienna from the right.
• Red bar: white on the left, Alizarin Crimson from the right.
• Green bar: white on the left, Thalo Green from the right.

Lowering chroma (graying) without changing value

• Reasons to gray: shadows, distance (color grays as it recedes), natural-looking color, and harmony.
• Two methods: black plus white gray, which works fairly well for cool colors and less well for warm ones; or complements. Complement pairs are orange/blue, red/green and yellow/violet.
• Find, match, add:
  1. Find the complement on the wheel.
  2. Match its value to the color being grayed, using white or a darkener.
  3. Add a small amount, about 10 percent.
• The goal is a grayer version of the color, not gray.
• Compare by holding paint on a palette knife or brush next to the target color. A match on the palette often looks off against the original.
• To gray blue or French Ultramarine Blue, use Burnt Sienna as the complement, with white if it's too dark. Mixed orange easily drifts too yellow or red and stops being a true complement.
• Dark yellows and violets (exception):
  • Earth tones (Yellow Ochre a little, Burnt Umber more) contain red and blue, so violet turns brown or warm instead of gray.
  • Fix by adding value-matched French Ultramarine Blue, either into the violet (making blue-violet) or after the violet is mixed with the yellow.
  • Violet fully complements only light yellow and slightly ochre-darkened yellow.
• Graying violet: the easiest way is a value-matched gray, which works better than yellow. Unless the violet is very light, a yellow complement needs extra value-matched French Ultramarine Blue.
• Mix that gray from French Ultramarine Blue plus Burnt Umber or Burnt Sienna. Ivory Black plus white also works.

Mixing blacks and grays

• Ivory Black is the recommended black pigment, but it looks like a dead spot straight from the tube. Add other color to give it life.
• Mix black from the darkest values of two complements. Add white for gray. Note each combination on your canvas.
• Orange/blue: Burnt Sienna plus French Ultramarine Blue is the fastest and most common.
  • It looks black immediately, and you can't judge the balance until you add white.
  • If the gray looks brown, add more blue. If it looks blue, add more Burnt Sienna.
  • Slightly warm or cool grays are more interesting than a perfect neutral.
• Red/green:
  • Alizarin Crimson plus Thalo Green makes an intense black and a slightly lavender gray, because Thalo Green is a cool, bluish green. Good for metal and silver, pearls and Spanish moss.
  • For a more neutral gray, use neutral red (Cadmium Red Hue plus Permanent Rose) with mixed green (Lemon Yellow Hue plus Thalo Blue), then add white.
• Yellow/violet: Burnt Umber plus violet (French Ultramarine Blue plus Permanent Rose) always looks too warm, and is rarely used. Add value-matched French Ultramarine Blue to neutralize it.
• Other pairs:
  • Burnt Umber plus French Ultramarine Blue gives a fast black and neutral gray.
  • Burnt Umber plus Thalo Blue gives gray-greens for rocks and tree trunks.

Shadow colors

• A body shadow or cast shadow is a darker, grayer version of the color of the surface it falls on. The object casting the shadow does not affect the color. A blue mug's shadow on pink cloth is a darker, grayer pink.
• A shadow on white is blue-gray or lavender-gray: mix an easy gray with French Ultramarine Blue and Burnt Sienna, emphasizing the blue.
• Do not use black for shadows. It shifts the hue of warm colors and dominates both warm and cool colors.
• Rule for shadows: darken, find, match, add.
  1. Darken the surface color with a darker color from the same family, to the value you want the shadow. This keeps it from getting too gray.
  2. Find the complement. For French Ultramarine Blue, Burnt Sienna is recommended over orange.
  3. Match the complement's value, adding white if needed.
  4. Add a small amount. Wipe most of the complement off the brush and use what's left.
• For tertiary colors the same rules hold. For dark yellows and violets, add extra value-matched French Ultramarine Blue to compensate for the earth tones.
• Exceptions:
  • Transparent or translucent objects: there is no shadow side, and a translucent object such as a petal is brighter there. Light passing through also throws color and light into the cast shadow.
  • Strong light: nearby colors reflect into each other and into cast shadows, for example a pink cloth into a blue mug, or an orange into its cast shadow.
• Light temperature:
  • Sun and incandescent light add a hint of yellow to sunlit colors. Add the merest touch of yellow to sunlit or warm-lit whites.
  • Use less yellow, or a cooler red, in outdoor shadows. Sunlit skin might be Cadmium Red Hue, Yellow Ochre and white, with more yellow in the lights. Then apply find, match, add to the shadows.