Color

#51576c

#51576c
hex#51576c
rgbrgb(81, 87, 108)
hslhsl(227, 14%, 37%)
oklchoklch(0.46 0.035 272.5)
Closest name: Blackwater (#545663)Relative luminance 0.0965

Colors that go with #51576c

Steel Blue, 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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#6c6651

#51646c · #59516c

#6c5157 · #576c51

Split-complementary

Open in tool →

#6c5951 · #646c51

#6c5164 · #6c6651 · #516c59

Contrast

#51576c as textRatioAAAA largeAAAFix
Aaon white
7.17:1passpasspassPasses AAA — no fix needed.
Aaon black
2.93:1failfailfail
  • AA: use #6e7591 as the text (4.62:1)
  • AAA: use #9196ac as the text (7.16:1)
  • AA: or shift the background to #cfcfcf (4.6:1)
  • AAA: or shift the background to #ffffff (7.17:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #51576c as the background.

Brands using this color

mcpConnect your agent — build around #51576c
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 #51576c and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/51576c-9ca0c4-df7a4e-221f2d-e9eff1?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