Convert, sample, mix and check color. All 9 tools below run locally in your browser. Nothing is uploaded.
Color work splits into three jobs: converting between the notations a codebase uses, checking that a pairing is actually legible, and building a set of colors that belong together. These tools cover all three, with a live preview at every step rather than a value you have to imagine.
The contrast checker scores against the published WCAG thresholds (4.5:1 for body text, 3.0 for large text, 7.0 for AAA), and the color blindness simulator shows the same palette through the common types of color vision deficiency, which catches the pairings that pass a ratio test but still fail in practice.
Palette Builder derives the harmonies from a single color, and Color Mixer fills in the steps between any two of them. Contrast Checker and Color Blindness Sim then tell you which of the results survive as text and which only work as decoration.
The ratio is measured on relative luminance, not on how vivid a color looks. White on a mid-tone blue or orange is the classic case: legible on a good screen, but it lands near 2.7:1, well under the threshold, and fails for anyone on a phone in daylight.
The Color Converter shows all three notations simultaneously with a live swatch, so editing any one of them updates the others.