Before building Color Unmixer, the sibling to Color Mixer, we checked an existing "color reverse calculator" to see how it handles the question that actually comes up: you see a color you like, and you're curious what two colors mixed together to make it.
The tool assumes you already know half the answer
The reverse calculator we checked requires a "Fixed Color" — one of the two ingredients — entered up front, and solves algebraically for the other: C = (T − F × R) / (1 − R). That's a genuinely useful calculation if you already know one ingredient and are missing the other. But it can't answer the actual curiosity-driven question — "I don't know either ingredient, what are some options?" — because its model requires knowing one from the start.
No known ingredient, and no silent approximation
This tool only needs the target color. It generates two candidate colors as mathematically symmetric points around the target in OKLab space (the same color-mixing model as Color Mixer) — which means their weighted combination reconstructs the target exactly, not as an approximation. The reverse calculator we checked clamps out-of-range results to a "Closest Possible Match" without always making clear how close is close; here, the verification preview shows you the reconstructed mix directly next to the target so you can see for yourself.
Since there's no single right answer
Infinitely many color pairs can mix to the same result — that's just true of color mixing, not a limitation of any particular tool. Rather than pretending there's one correct answer, this tool gives you a hue axis and spread to adjust, so you can explore different valid ingredient pairs for the same target.
