Color

#3f4a69

#3f4a69
hex#3f4a69
rgbrgb(63, 74, 105)
hslhsl(224, 25%, 33%)
oklchoklch(0.413 0.054 268.9)
Closest name: Bonne Nuit (#3a4866)Relative luminance 0.0697

Colors that go with #3f4a69

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 →

#695e3f

#3f5f69 · #493f69

#693f4a · #4a693f

Split-complementary

Open in tool →

#69493f · #5f693f

#693f5f · #695e3f · #3f6949

Contrast

#3f4a69 as textRatioAAAA largeAAAFix
Aaon white
8.77:1passpasspassPasses AAA — no fix needed.
Aaon black
2.39:1failfailfail
  • AA: use #6676a3 as the text (4.69:1)
  • AAA: use #8996b8 as the text (7.12:1)
  • AA: or shift the background to #bababa (4.52:1)
  • AAA: or shift the background to #e6e6e6 (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f4a69 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 #3f4a69
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 #3f4a69 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f4a69-9ca2c4-df724e-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