Color

#3f4178

#3f4178
hex#3f4178
rgbrgb(63, 65, 120)
hslhsl(238, 31%, 36%)
oklchoklch(0.401 0.091 279.9)
Closest name: Evening Magic (#363e7d)Relative luminance 0.0619

Colors that go with #3f4178

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 →

#78763f

#3f5e78 · #5a3f78

#783f41 · #41783f

Split-complementary

Open in tool →

#785a3f · #5e783f

#783f5e · #78763f · #3f785a

Contrast

#3f4178 as textRatioAAAA largeAAAFix
Aaon white
9.38:1passpasspassPasses AAA — no fix needed.
Aaon black
2.24:1failfailfail
  • AA: use #6c6eb2 as the text (4.51:1)
  • AAA: use #9193c5 as the text (7.18:1)
  • AA: or shift the background to #b5b5b5 (4.57:1)
  • AAA: or shift the background to #e0e0e0 (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f4178 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 #3f4178
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 #3f4178 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f4178-9f9cc4-df944e-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