Color

#3d4e81

#3d4e81
hex#3d4e81
rgbrgb(61, 78, 129)
hslhsl(225, 36%, 37%)
oklchoklch(0.434 0.087 268.7)
Closest name: Assassin (#2d4f83)Relative luminance 0.0803

Colors that go with #3d4e81

Sea Green, Steel Blue and 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.

Real palettes that use #3d4e81

Tints & shades

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

Harmonies

Complementary

Open in tool →

#806f3c

#3c6f80 · #4d3c80

#803c4d · #4d803c

Split-complementary

Open in tool →

#804d3c · #6f803c

#803c6f · #806f3c · #3c804d

Contrast

#3d4e81 as textRatioAAAA largeAAAFix
Aaon white
8.06:1passpasspassPasses AAA — no fix needed.
Aaon black
2.61:1failfailfail
  • AA: use #5c72b2 as the text (4.5:1)
  • AAA: use #8696c6 as the text (7.19:1)
  • AA: or shift the background to #c2c2c2 (4.53:1)
  • AAA: or shift the background to #f0f0f0 (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3d4e81 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

#3d4e81 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3d4e81
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 #3d4e81 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3d4e81-9ca1c4-df754e-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