Color

#515b70

#515b70
hex#515b70
rgbrgb(81, 91, 112)
hslhsl(221, 16%, 38%)
oklchoklch(0.471 0.036 265)
Closest name: Blackwater (#545663)Relative luminance 0.104

Colors that go with #515b70

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 →

#706751

#516b70 · #575170

#70515b · #5b7051

Split-complementary

Open in tool →

#705751 · #6b7051

#70516b · #706751 · #517057

Contrast

#515b70 as textRatioAAAA largeAAAFix
Aaon white
6.82:1passpassfail
  • AAA: use #4f596d as the text (7.04:1)
Aaon black
3.08:1failpassfail
  • AA: use #697691 as the text (4.6:1)
  • AAA: use #8c96ab as the text (7.07:1)
  • AA: or shift the background to #d4d4d4 (4.6:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #515b70 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 #515b70
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 #515b70 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/515b70-9ca4c4-df6b4e-211f2d-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