Color

#515381

#515381
hex#515381
rgbrgb(81, 83, 129)
hslhsl(238, 23%, 41%)
oklchoklch(0.461 0.074 281.1)
Closest name: Dusk (#4e5481)Relative luminance 0.0952

Colors that go with #515381

Steel Blue, Blue and Crimson 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.

Real palettes that use #515381

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#817f51

#516a81 · #675181

#815152 · #528151

Split-complementary

Open in tool →

#816751 · #6a8151

#81516a · #817f51 · #518167

Contrast

#515381 as textRatioAAAA largeAAAFix
Aaon white
7.23:1passpasspassPasses AAA — no fix needed.
Aaon black
2.9:1failfailfail
  • AA: use #6f71a5 as the text (4.58:1)
  • AAA: use #9193ba as the text (7.09:1)
  • AA: or shift the background to #cccccc (4.5:1)
  • AAA: or shift the background to #fcfcfc (7.05:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #515381 as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

mcpConnect your agent — build around #515381
live endpoint

Point 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.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #515381 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/515381-9f9cc4-df944e-251f2d-e9edf1?lock=0&style=vibrant

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Machine-readable: color.md