Color

#3d517b

#3d517b
hex#3d517b
rgbrgb(61, 81, 123)
hslhsl(221, 34%, 36%)
oklchoklch(0.438 0.074 264.2)
Closest name: Assassin (#2d4f83)Relative luminance 0.0831

Colors that go with #3d517b

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.

Tints & shades

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

Harmonies

Complementary

Open in tool →

#7b673d

#3d707b · #483d7b

#7b3d50 · #507b3d

Split-complementary

Open in tool →

#7b483d · #707b3d

#7b3d70 · #7b673d · #3d7b48

Contrast

#3d517b as textRatioAAAA largeAAAFix
Aaon white
7.89:1passpasspassPasses AAA — no fix needed.
Aaon black
2.66:1failfailfail
  • AA: use #5b75ae as the text (4.6:1)
  • AAA: use #8195c1 as the text (7:1)
  • AA: or shift the background to #c4c4c4 (4.52:1)
  • AAA: or shift the background to #f2f2f2 (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 #3d517b 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 #3d517b
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 #3d517b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3d517b-9ca4c4-df6b4e-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