Harbour
Open in tool →Steel blue and haze with a buoy orange on a pale grey — the maritime palette every port town uses for a reason.
Color
#31587d
#31587d
hex
#31587drgb
rgb(49, 88, 125)hsl
hsl(209, 44%, 34%)oklch
oklch(0.449 0.076 248.7)Closest name: Beyond the Sea (#005784)Relative luminance 0.0911
Colors that go with #31587d
Sienna, Blue and Cadet Blue lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.
Sienna #a0522d
complementaryshippedSienna sits directly opposite #31587d on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped7 real palettes, including Tesco's brand system and CVS's brand system put Blue beside #31587d, as the supporting colour.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #31587d: 4 real palettes, including Dusk and Open House, as the supporting colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #31587d: 4 real palettes, including Coca-Cola's brand system and Gopro's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #31587d in 14 real palettes, including Codecademy's brand system and Walgreens's brand system, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #31587d: 16 real palettes, including HP's brand system and Dutch Bros's brand system, as the accent.
Firebrick #b22222
shippedDesigners have shipped Firebrick with #31587d: 4 real palettes, including Fireside and Wendy's's brand system, as the lead colour.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #31587d: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #31587d
Tints & shades
Harmonies
Contrast
| #31587d as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 7.44:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.82:1 | fail | fail | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #31587d as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Palettes built around it
Fonts for this mood
#31587d reads as cool, modern. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #31587d
live endpointPoint any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #31587d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/31587d-9cacc4-df4e4e-1f212d-e9f1f1?lock=0&style=vibrantWant the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.
Machine-readable: color.md