Color

#51addb

#51addb
hex#51addb
rgbrgb(81, 173, 219)
hslhsl(200, 66%, 59%)
oklchoklch(0.71 0.11 233)
Closest name: Cousteau (#55a9d6)Relative luminance 0.3675

Colors that go with #51addb

Charcoal, Peru and Amber 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 →

#db7f51

#51dbc4 · #5168db

#db51ad · #addb51

Split-complementary

Open in tool →

#db5168 · #dbc451

#c451db · #db7f51 · #68db51

Contrast

#51addb as textRatioAAAA largeAAAFix
Aaon white
2.51:1failfailfail
  • AA: use #237ca9 as the text (4.64:1)
  • AAA: use #1a5d7f as the text (7.2:1)
  • AA: or shift the background to #383838 (4.66:1)
  • AAA: or shift the background to #171717 (7.13:1)
Aaon black
8.35:1passpasspassPasses AAA — no fix needed.

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #51addb as the background.

Brands using this color

Fonts for this mood

#51addb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #51addb
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 #51addb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/51addb-9cb2c4-df4e64-1f232d-e9f1f0?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