Color

#5191d2

#5191d2
hex#5191d2
rgbrgb(81, 145, 210)
hslhsl(210, 59%, 57%)
oklchoklch(0.642 0.118 250.5)
Closest name: Blue Bay (#619ad6)Relative luminance 0.2665

Colors that go with #5191d2

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 →

#d29151

#51d2d2 · #5151d2

#d25191 · #91d251

Split-complementary

Open in tool →

#d25151 · #d2d251

#d251d2 · #d29151 · #51d251

Contrast

#5191d2 as textRatioAAAA largeAAAFix
Aaon white
3.32:1failpassfail
  • AA: use #3178bf as the text (4.6:1)
  • AAA: use #25598e as the text (7.25:1)
  • AA: or shift the background to #262626 (4.56:1)
Aaon black
6.33:1passpassfail
  • AAA: use #619cd6 as the text (7.23:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #5191d2 as the background.

Brands using this color

Fonts for this mood

#5191d2 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #5191d2
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 #5191d2 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/5191d2-9cabc4-df514e-1f202d-e9f1f1?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