Color

#3f5664

#3f5664
hex#3f5664
rgbrgb(63, 86, 100)
hslhsl(203, 23%, 32%)
oklchoklch(0.44 0.036 235.4)
Closest name: Arctic Nights (#345c61)Relative luminance 0.0863

Colors that go with #3f5664

Sienna, 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.

Real palettes that use #3f5664

Tints & shades

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

Harmonies

Complementary

Open in tool →

#644d3f

#3f6460 · #3f4364

#643f56 · #56643f

Split-complementary

Open in tool →

#643f43 · #64603f

#603f64 · #644d3f · #43643f

Contrast

#3f5664 as textRatioAAAA largeAAAFix
Aaon white
7.7:1passpasspassPasses AAA — no fix needed.
Aaon black
2.73:1failfailfail
  • AA: use #58798d as the text (4.53:1)
  • AAA: use #7b9aad as the text (7.07:1)
  • AA: or shift the background to #c7c7c7 (4.56:1)
  • AAA: or shift the background to #f5f5f5 (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f5664 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 #3f5664
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 #3f5664 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f5664-9cb0c4-df4e5d-1f222d-e9f1f0?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