Color

#377bf1

#377bf1
hex#377bf1
rgbrgb(55, 123, 241)
hslhsl(218, 87%, 58%)
oklchoklch(0.604 0.191 260.6)
Closest name: Blue Öyster Cult (#5577ee)Relative luminance 0.2133

Colors that go with #377bf1

Charcoal, Crimson 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 →

#f1ad37

#37d8f1 · #5037f1

#f1377b · #7bf137

Split-complementary

Open in tool →

#f15037 · #d8f137

#f137d8 · #f1ad37 · #37f150

Contrast

#377bf1 as textRatioAAAA largeAAAFix
Aaon white
3.99:1failpassfail
  • AA: use #246ef0 as the text (4.6:1)
  • AAA: use #0e50c4 as the text (7.09:1)
  • AA: or shift the background to #141414 (4.62:1)
Aaon black
5.27:1passpassfail
  • AAA: use #5d94f4 as the text (7.01:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #377bf1 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#377bf1 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #377bf1
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 #377bf1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/377bf1-9ca6c4-df644e-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