#9FD7C8 · #CDC2ED
Four independent scores (read the one that fits your goal): Readability 1/100 (fail) · Harmony 49/100 (triadic (soft)) · Distinguishable 28/100 (hard to tell apart) · Match 13/100 (different). There is no single “good/bad” — a pair can clash for text yet be great for an outfit.
Light Blue and Periwinkle are very different (ΔE 40). They have distinctly different hues (91° apart) and their lightness is similar, so they read as two same-weight colours.
Light Blue text on Periwinkle: 1.04:1 (Fail); Periwinkle text on Light Blue: 1.04:1 (Fail). Neither meets AA at body size — nudging one color to #275D51 clears it.
Triadic (soft) — workable but not a textbook harmony (harmony 49/100). 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 #275D51 clears AA.
Their CIE76 ΔE is about 40 — very different.
clearly different colours (ΔE 40).
Explore each color: Light Blue #9FD7C8 · Periwinkle #CDC2ED · Shades: Light Blue shades · Periwinkle shades · Contrast checker →