#101D2F · #271A05
Four independent scores (read the one that fits your goal): Readability 0/100 (fail) · Harmony 99/100 (complementary) · Distinguishable 64/100 (somewhat similar) · Match 40/100 (different). There is no single “good/bad” — a pair can clash for text yet be great for an outfit.
Deep Blue and Deep Yellow are a clear pair (ΔE 27). They have near-opposite hues (178° apart) and their lightness is similar, so they read as two same-weight colours.
Deep Blue text on Deep Yellow: 1.00:1 (Fail); Deep Yellow text on Deep Blue: 1.00:1 (Fail). Neither meets AA at body size — nudging one color to #74859B clears it.
Complementary — complementary — a recognised, balanced pairing (harmony 99/100). This is about how they look together (clothing, interiors, branding), independent of text contrast.
Not at body size — the best direction is only 1.0:1, below the 4.5:1 minimum. Nudging one colour to #74859B clears AA.
Their CIE76 ΔE is about 27 — a clear pair.
clearly different colours (ΔE 27).
Explore each color: Deep Blue #101D2F · Deep Yellow #271A05 · Shades: Deep Blue shades · Deep Yellow shades · Contrast checker →