Color Reverse Calculator
Know your target color? Enter one or two fixed colors and their ratios to calculate the missing RGB color.
Digital RGB calculations, not physical paint or ink formulas.
Try a quick example
Try a reverse calculation or find the RGB opposite of a target color.
Fixed Color 1
Fixed Color 2
Target Color
Target color is unreachable. Showing closest possible match.
Opposite color
RGB channel inversion of the current .
How the reverse color calculation works
Enter a fixed color, target color and the fixed color's percentage. The missing color is calculated per RGB channel with C = (T - F * R) / (1 - R). For example, black at 50% and a target of RGB(100, 100, 100) require RGB(200, 200, 200).
Three-color reverse calculations
With two fixed colors, choose their percentages and leave a positive percentage for the unknown color: r3 = 1 - r1 - r2. Then C = (T - F1 * r1 - F2 * r2) / r3. You supply the ratios; this tool does not automatically solve for them.
What if the target is unreachable?
If a required channel falls outside 0 to 255, the tool shows a warning and clamps the preview to that range. The preview is an approximation and cannot reproduce the target with the selected inputs.
What does the Pantone result mean?
The result is matched to the nearest RGB entry in the available coated palette. It is an approximate screen reference, not a Pantone ink recipe, a guaranteed printed match, or a perceptual color-distance measurement.
RGB Color Mixing vs Paint Mixing
These calculations use weighted digital RGB values. Physical paints and inks need material-specific mixing models. To blend two known digital colors instead, open the Color Mixing Calculator.
Find the Opposite Color
The opposite-color result uses 255 - channel on your target color. This is RGB inversion, not a hue-wheel complementary-color calculation.
Related color tool
Pick an exact HEX or RGB value from an uploaded image, then use it in this calculator.