Color

#3f4773

#3f4773
hex#3f4773
rgbrgb(63, 71, 115)
hslhsl(231, 29%, 35%)
oklchoklch(0.412 0.074 274.8)
Closest name: Bonne Nuit (#3a4866)Relative luminance 0.068

Colors that go with #3f4773

Steel Blue, Blue and Cadet Blue 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 →

#736b3f

#3f6173 · #513f73

#733f47 · #47733f

Split-complementary

Open in tool →

#73513f · #61733f

#733f61 · #736b3f · #3f7351

Contrast

#3f4773 as textRatioAAAA largeAAAFix
Aaon white
8.9:1passpasspassPasses AAA — no fix needed.
Aaon black
2.36:1failfailfail
  • AA: use #6872ac as the text (4.59:1)
  • AAA: use #8c94c0 as the text (7.11:1)
  • AA: or shift the background to #bababa (4.58:1)
  • AAA: or shift the background to #e6e6e6 (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 #3f4773 as the background.

Brands using this color

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

mcpConnect your agent — build around #3f4773
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 #3f4773 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f4773-9c9ec4-df834e-231f2d-e9eef1?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