The main difference between Cerulean and Cobalt is hue — Cerulean is a cool cyan, while Cobalt is a cool blue. Cerulean (#007BA7) and Cobalt (#0047AB) are similar colors often confused. They differ in brightness, saturation, and undertone, making each better suited for different design contexts.
Four real design scenarios, with the recommended pick based on hue, saturation, and WCAG contrast.
Cerulean is more saturated (100% HSL vs 100%) so it reads as bolder and more memorable at logo scale, while Cobalt can feel washed out when printed small.
Cobalt hits a 8.44:1 WCAG contrast against white — safer for text-heavy interfaces — where Cerulean only reaches 4.78:1 and risks failing AA at small body sizes.
Cobalt is a cool-leaning tone that flatters spring/summer collections and warmer skin undertones, while Cerulean leans cooler and is better suited to autumn/winter layering.
Cerulean is the more muted of the two (100% saturation) and sits more calmly on large wall surfaces, while Cobalt's higher chroma can overwhelm a room when used beyond accent pieces.
Cerulean (#007BA7) is a dark, vivid cyan with a cool undertone — it feels rich, serious, substantial and bright, energetic, eye-catching.
Cobalt (#0047AB) is a dark, vivid blue with a cool undertone — it feels rich, serious, substantial and bright, energetic, eye-catching.
Text legibility depends on the contrast ratio between foreground and background. WCAG 2.1 AA requires at least 4.5:1 for normal text and 3:1 for large text; AAA requires 7:1. Use these numbers to choose accessible combinations for your design.
Each color has a dedicated page with shades, tints, CSS name, pairings, and color psychology.