Color

#3780cd

#3780cd
hex#3780cd
rgbrgb(55, 128, 205)
hslhsl(211, 60%, 51%)
oklchoklch(0.591 0.139 252.3)
Closest name: Haddock’s Sweater (#277aba)Relative luminance 0.2066

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#cd8537

#37cbcd · #3a37cd

#cd3780 · #80cd37

Split-complementary

Open in tool →

#cd3a37 · #cbcd37

#cd37cb · #cd8537 · #37cd3a

Contrast

#3780cd as textRatioAAAA largeAAAFix
Aaon white
4.09:1failpassfail
  • AA: use #3178c4 as the text (4.55:1)
  • AAA: use #255a93 as the text (7.09:1)
  • AA: or shift the background to #141414 (4.5:1)
Aaon black
5.13:1passpassfail
  • AAA: use #609ad7 as the text (7.1:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3780cd as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#3780cd reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3780cd
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #3780cd and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3780cd-9cabc4-df534e-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