Color

#3f4088

#3f4088
hex#3f4088
rgbrgb(63, 64, 136)
hslhsl(239, 37%, 39%)
oklchoklch(0.41 0.117 279.3)
Closest name: darkslateblue (#483d8b)Relative luminance 0.065

Colors that go with #3f4088

Charcoal, 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 →

#88873f

#3f6588 · #623f88

#883f40 · #40883f

Split-complementary

Open in tool →

#88623f · #65883f

#883f65 · #88873f · #3f8862

Contrast

#3f4088 as textRatioAAAA largeAAAFix
Aaon white
9.13:1passpasspassPasses AAA — no fix needed.
Aaon black
2.3:1failfailfail
  • AA: use #6c6ebc as the text (4.59:1)
  • AAA: use #8f90cc as the text (7.03:1)
  • AA: or shift the background to #b8b8b8 (4.6:1)
  • AAA: or shift the background to #e3e3e3 (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 #3f4088 as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#3f4088 reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f4088
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 #3f4088 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f4088-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