Blue and red color palettes

Blue and red are about 133° apart on the color wheel, close to a triadic relationship: clearly different, but less of a clash than true opposites. Pairings like this feel lively and balanced, and they leave room for a third hue or a neutral to tie them together.

In practice, blue recedes and reads as trustworthy, so it suits large surfaces and primary actions, while red brings urgency and is best kept to calls to action and highlights. The palettes below combine both families, strongest matches first; open any of them to see its contrast matrix and copy the hex codes, CSS variables or Tailwind config.

Hue contrast is not text contrast: two colors can look completely different and still fail WCAG as text and background. Every palette page shows which pairs pass, and the contrast checker suggests the nearest passing shade.