Color

#3d4d71

#3d4d71
hex#3d4d71
rgbrgb(61, 77, 113)
hslhsl(222, 30%, 34%)
oklchoklch(0.423 0.064 265.4)
Closest name: Bonne Nuit (#3a4866)Relative luminance 0.0749

Colors that go with #3d4d71

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 →

#71613d

#3d6671 · #473d71

#713d4c · #4c713d

Split-complementary

Open in tool →

#71473d · #66713d

#713d66 · #71613d · #3d7147

Contrast

#3d4d71 as textRatioAAAA largeAAAFix
Aaon white
8.41:1passpasspassPasses AAA — no fix needed.
Aaon black
2.5:1failfailfail
  • AA: use #6076a9 as the text (4.66:1)
  • AAA: use #8495bd as the text (7.01:1)
  • AA: or shift the background to #bfbfbf (4.57:1)
  • AAA: or shift the background to #ebebeb (7.05:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3d4d71 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 #3d4d71
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 #3d4d71 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3d4d71-9ca3c4-df6e4e-211f2d-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