#009AAC · #FE0B02
Four independent scores (read the one that fits your goal): Readability 4/100 (fail) · Harmony 100/100 (complementary) · Distinguishable 100/100 (easy to tell apart) · Match 0/100 (different). There is no single “good/bad” — a pair can clash for text yet be great for an outfit.
Dark Vivid Cyan and Red are very different (ΔE 137). They have near-opposite hues (176° apart) and their lightness is similar, so they read as two same-weight colours.
Dark Vivid Cyan text on Red: 1.18:1 (Fail); Red text on Dark Vivid Cyan: 1.18:1 (Fail). Neither meets AA at body size — nudging one color to #001A1F clears it.
Complementary — complementary — a recognised, balanced pairing (harmony 100/100). This is about how they look together (clothing, interiors, branding), independent of text contrast.
Not at body size — the best direction is only 1.2:1, below the 4.5:1 minimum. Nudging one colour to #001A1F clears AA.
Their CIE76 ΔE is about 137 — very different.
clearly different colours (ΔE 137).
Explore each color: Dark Vivid Cyan #009AAC · Red #FE0B02 · Shades: Dark Vivid Cyan shades · Red shades · Contrast checker →