Color

#517bdb

#517bdb
hex#517bdb
rgbrgb(81, 123, 219)
hslhsl(222, 66%, 59%)
oklchoklch(0.6 0.154 264.5)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2103

Colors that go with #517bdb

Charcoal, Sea Green and Copper 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 →

#dbb251

#51c0db · #6d51db

#db517b · #7bdb51

Split-complementary

Open in tool →

#db6d51 · #c0db51

#db51c0 · #dbb251 · #51db6d

Contrast

#517bdb as textRatioAAAA largeAAAFix
Aaon white
4.03:1failpassfail
  • AA: use #4571d9 as the text (4.55:1)
  • AAA: use #2551b6 as the text (7.16:1)
  • AA: or shift the background to #141414 (4.57:1)
Aaon black
5.21:1passpassfail
  • AAA: use #7395e2 as the text (7.13:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #517bdb as the background.

Brands using this color

Fonts for this mood

#517bdb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #517bdb
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 #517bdb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/517bdb-9ca3c4-df6e4e-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