Color

#517df5

#517df5
hex#517df5
rgbrgb(81, 125, 245)
hslhsl(224, 89%, 64%)
oklchoklch(0.621 0.186 266)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2301

Colors that go with #517df5

Charcoal, Red 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 →

#f5c951

#51cff5 · #7851f5

#f5517d · #7df551

Split-complementary

Open in tool →

#f57851 · #cff551

#f551cf · #f5c951 · #51f578

Contrast

#517df5 as textRatioAAAA largeAAAFix
Aaon white
3.75:1failpassfail
  • AA: use #396bf3 as the text (4.59:1)
  • AAA: use #0d45de as the text (7.18:1)
  • AA: or shift the background to #1c1c1c (4.55:1)
Aaon black
5.6:1passpassfail
  • AAA: use #6e93f7 as the text (7.18:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #517df5 as the background.

Brands using this color

Fonts for this mood

#517df5 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #517df5
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 #517df5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/517df5-9ca2c4-df724e-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