The main difference between Indigo and Navy is a subtle hue shift within the purple family — the hue angle moves 35° between them, changing the perceived undertone. Indigo (#4B0082) is a deep purple-blue originally made from the Indigofera plant, while Navy (#000080) is a very dark pure blue with no purple. Indigo leans purple; navy is straight blue.
Four real design scenarios, with the recommended pick based on hue, saturation, and WCAG contrast.
Indigo is more saturated (100% HSL vs 100%) so it reads as bolder and more memorable at logo scale, while Navy can feel washed out when printed small.
Navy hits a 16.01:1 WCAG contrast against white — safer for text-heavy interfaces — where Indigo only reaches 12.95:1 and risks failing AA at small body sizes.
Indigo is a warm tone that flatters spring/summer collections and warmer skin undertones, while Navy leans cooler and is better suited to autumn/winter layering.
Indigo is the more muted of the two (100% saturation) and sits more calmly on large wall surfaces, while Navy's higher chroma can overwhelm a room when used beyond accent pieces.
Indigo (RGB 75,0,130) is a deep purple-blue named after the Indigofera plant dye traded across the Indian Ocean for centuries. It's one of Newton's original seven rainbow colors and reads as mystical, spiritual, and jewel-like.
Navy (RGB 0,0,128) is the darkest named blue, with no red content and no purple cast. Named after the British Royal Navy uniform (1748), it reads as formal, authoritative, and conservative.
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.