Color

#518bdb

#518bdb
hex#518bdb
rgbrgb(81, 139, 219)
hslhsl(215, 66%, 59%)
oklchoklch(0.634 0.136 256.8)
Closest name: Blue Jay (#5588dd)Relative luminance 0.2533

Colors that go with #518bdb

Charcoal, Copper 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 →

#dba251

#51d0db · #5d51db

#db518b · #8bdb51

Split-complementary

Open in tool →

#db5d51 · #d0db51

#db51d0 · #dba251 · #51db5d

Contrast

#518bdb as textRatioAAAA largeAAAFix
Aaon white
3.46:1failpassfail
  • AA: use #3074d5 as the text (4.58:1)
  • AAA: use #2156a1 as the text (7.22:1)
  • AA: or shift the background to #212121 (4.65:1)
Aaon black
6.07:1passpassfail
  • AAA: use #6799e0 as the text (7.21:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #518bdb as the background.

Brands using this color

Fonts for this mood

#518bdb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #518bdb
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 #518bdb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/518bdb-9ca8c4-df5d4e-201f2d-e9f0f1?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