色変換 & コントラストチェッカー
HEX / RGB / HSL / OKLCH + WCAG コントラスト
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色変換（HEX / RGB / HSL / OKLCH）
A modern color converter that supports CSS Color 4's perceptually uniform OKLCH space, in addition to traditional HEX, RGB and HSL. Includes WCAG 2.1 contrast ratio against white and black so you can pick accessible foregrounds.
- HEX (3 / 4 / 6 / 8 digits)
- RGB / RGBA
- HSL / HSLA
- OKLCH (CSS Color 4, perceptually uniform)
- WCAG 2.1 contrast vs white and black
- Live preview swatch
FAQ
What is OKLCH?
OKLCH is a perceptually uniform color space introduced in CSS Color Level 4. Equal numerical changes correspond to roughly equal perceived changes — ideal for harmonious palettes.
How do I read the contrast ratio?
WCAG 2.1: 4.5:1 = AA for normal text, 3:1 = AA for large text, 7:1 = AAA. The tool tells you the rating against pure white and black.