Prussian Blue and Navy are near-identical blue shades — they sit within a few degrees of hue, lightness, and saturation of each other. The difference is mostly in name and historical use. Prussian Blue (#003153) is a deep dark blue with a slight green undertone, historically one of the first synthetic pigments (1704), while Navy (#000080) is a pure dark blue with no green shift. Prussian leans slightly cyan; navy is straight blue.
Four real design scenarios, with the recommended pick based on hue, saturation, and WCAG contrast.
Prussian Blue 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 16.56:1 WCAG contrast against white — safer for text-heavy interfaces — where Prussian Blue only reaches 13.43:1 and risks failing AA at small body sizes.
Prussian Blue is a cool-leaning tone that flatters spring/summer collections and warmer skin undertones, while Navy leans cooler and is better suited to autumn/winter layering.
Prussian Blue 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.
Prussian Blue (RGB 0,49,83) is a very dark blue with a hint of green, famous as the world's first modern synthetic pigment, accidentally discovered in Berlin in 1704. It became the signature blue of Japanese woodblock prints like Hokusai's Great Wave.
Navy (RGB 0,0,128) is a pure dark blue with no red or green mixed in — the original British Royal Navy uniform color standardized in 1748. It reads as formal, authoritative, and corporate.
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.