Color

#3f4869

#3f4869
hex#3f4869
rgbrgb(63, 72, 105)
hslhsl(227, 25%, 33%)
oklchoklch(0.408 0.057 272)
Closest name: Bonne Nuit (#3a4866)Relative luminance 0.0671

Colors that go with #3f4869

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 →

#69603f

#3f5d69 · #4b3f69

#693f48 · #48693f

Split-complementary

Open in tool →

#694b3f · #5d693f

#693f5d · #69603f · #3f694b

Contrast

#3f4869 as textRatioAAAA largeAAAFix
Aaon white
8.97:1passpasspassPasses AAA — no fix needed.
Aaon black
2.34:1failfailfail
  • AA: use #6673a3 as the text (4.55:1)
  • AAA: use #8c96ba as the text (7.19:1)
  • AA: or shift the background to #b8b8b8 (4.52:1)
  • AAA: or shift the background to #e6e6e6 (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 #3f4869 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 #3f4869
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 #3f4869 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f4869-9ca0c4-df7a4e-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