Color

#3f4078

#3f4078
hex#3f4078
rgbrgb(63, 64, 120)
hslhsl(239, 31%, 36%)
oklchoklch(0.399 0.093 280.5)
Closest name: Evening Magic (#363e7d)Relative luminance 0.0608

Colors that go with #3f4078

Steel Blue, Blue and Crimson 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 →

#78773f

#3f5d78 · #5b3f78

#783f40 · #40783f

Split-complementary

Open in tool →

#785b3f · #5d783f

#783f5d · #78773f · #3f785b

Contrast

#3f4078 as textRatioAAAA largeAAAFix
Aaon white
9.48:1passpasspassPasses AAA — no fix needed.
Aaon black
2.22:1failfailfail
  • AA: use #6f70b3 as the text (4.64:1)
  • AAA: use #9192c5 as the text (7.12:1)
  • AA: or shift the background to #b3b3b3 (4.52:1)
  • AAA: or shift the background to #dedede (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f4078 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 #3f4078
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 #3f4078 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f4078-a09cc4-df964e-251f2d-e9edf1?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