How much of each color do I need to mix a liter or gallon of a custom shade?
Ratios stay the same at any volume — multiply every part by the same factor. For 1 liter (1000 ml) of a 70% / 20% / 10% recipe, that's 700 ml base + 200 ml modifier + 100 ml white. Mix in batches of no more than 1 liter, and always reserve a small swatch for matching the next batch.
Step-by-step
Convert percentages to volume
Multiply each percentage by your target volume. 70% of 1 L = 700 ml. 20% of 1 gallon (3785 ml) = 757 ml. Use a measuring cup with ml markings.
Mix in batches under 1 liter
Larger batches under-mix at the edges. For walls or murals, mix multiple 1 L batches and combine them at the end into a single bucket — that 'boxing' step evens out small variations.
Reserve a reference swatch
Paint out a 3×3 cm dried swatch from the first batch and keep it labeled. Match every subsequent batch to that swatch under the same light.
Account for waste
Mix 10–15% more than you think you need. Re-matching a custom color mid-project is much harder than overshooting once at the start.
Get the recipe, then scale it
Chromilla returns percentage ratios — multiply by your target volume to get ml, L or gallons.
Open Chromilla →Frequently asked questions
- Do ratios change at large volumes?
- No. Pigment-to-pigment ratios are dimensionless — they're the same at 10 ml or 10 liters. What changes is mixing technique: bigger volumes need longer stirring to fully homogenize.
- How long does mixed paint stay usable?
- Acrylic: a few hours wet, indefinitely if sealed airtight. Oil: days to weeks in a closed jar with a thin layer of clove oil on top. Watercolour: re-wettable forever once dry on a palette.