Color

#515b8a

#515b8a
hex#515b8a
rgbrgb(81, 91, 138)
hslhsl(229, 26%, 43%)
oklchoklch(0.483 0.077 274)
Closest name: Dusk (#4e5481)Relative luminance 0.1107

Colors that go with #515b8a

Charcoal, Sea Green and Steel 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.

Real palettes that use #515b8a

Tints & shades

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

Harmonies

Complementary

Open in tool →

#8a8051

#51788a · #63518a

#8a515c · #5c8a51

Split-complementary

Open in tool →

#8a6351 · #788a51

#8a5178 · #8a8051 · #518a63

Contrast

#515b8a as textRatioAAAA largeAAAFix
Aaon white
6.54:1passpassfail
  • AAA: use #4b5581 as the text (7.2:1)
Aaon black
3.21:1failpassfail
  • AA: use #6873a6 as the text (4.59:1)
  • AAA: use #8b94bb as the text (7.05:1)
  • AA: or shift the background to #d9d9d9 (4.63:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #515b8a 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

mcpConnect your agent — build around #515b8a
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 #515b8a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/515b8a-9c9fc4-df7e4e-231f2d-e9eef1?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