Color

#3f6478

#3f6478
hex#3f6478
rgbrgb(63, 100, 120)
hslhsl(201, 31%, 36%)
oklchoklch(0.484 0.053 233)
Closest name: Atlantis (#336172)Relative luminance 0.1153

Colors that go with #3f6478

Charcoal, Royal Blue and Sienna 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 →

#78533f

#3f7870 · #3f4878

#783f64 · #64783f

Split-complementary

Open in tool →

#783f48 · #78703f

#703f78 · #78533f · #48783f

Contrast

#3f6478 as textRatioAAAA largeAAAFix
Aaon white
6.35:1passpassfail
  • AAA: use #3a5c6e as the text (7.15:1)
Aaon black
3.31:1failpassfail
  • AA: use #4d7b93 as the text (4.57:1)
  • AAA: use #6f9cb3 as the text (7.08:1)
  • AA: or shift the background to #d9d9d9 (4.5:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f6478 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 #3f6478
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 #3f6478 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f6478-9cb1c4-df4e62-1f222d-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