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Colour Mixing Ratio Calculator — Paint Mixing Guide
Work out primary colour ratios to mix a target colour family for any paint medium.
How We Calculate This
How Colour Mixing Ratios Work
Pigment parts = colour family recipe × warmth × opacity
Each colour family starts from a base ratio of the RYB artist primaries — green is yellow + blue, purple is red + blue, earth tones lean on red + yellow. The warmth slider shifts the balance towards warm (more red/yellow) or cool (more blue). Lightness sets how much white and black to add. The opacity factor thins the whole pigment load uniformly for glazing, so the recipe ratio holds while the charge drops. The paint medium nudges the white amount to offset the drying shift — acrylic dries darker so it adds a little more white, watercolour dries lighter so it holds white back.
Frequently Asked Questions
Mixing your own colours gives you far more control over hue, saturation and value. You can match any colour exactly and develop a deeper understanding of colour relationships. It also reduces the number of tubes you need to carry.
Yes. Acrylics dry slightly darker and shift in hue. Oils stay true to the wet mix. Watercolours dry lighter. Always test your mix on a scrap piece and let it dry before applying to your painting.
Parts are relative proportions, not absolute amounts. If a mix calls for 3 parts red and 2 parts yellow, you could use 3 ml red and 2 ml yellow, or 3 knife-loads of red and 2 of yellow. The ratio stays the same.
Add the complementary colour in small amounts to reduce saturation without changing value. For example, add a touch of green to dull a red. Alternatively, add grey or a mix of all three primaries. Avoid adding black, which can create muddy results.
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Last updated: March 2026
All calculations are estimates. Always verify quantities before purchasing materials.