Color

#3f459d

#3f459d
hex#3f459d
rgbrgb(63, 69, 157)
hslhsl(236, 43%, 43%)
oklchoklch(0.436 0.141 275.9)
Closest name: Blueberry (#464196)Relative luminance 0.0775

Colors that go with #3f459d

Charcoal, Sea Green and Steel 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 →

#9d973f

#3f749d · #673f9d

#9d3f45 · #459d3f

Split-complementary

Open in tool →

#9d673f · #749d3f

#9d3f74 · #9d973f · #3f9d67

Contrast

#3f459d as textRatioAAAA largeAAAFix
Aaon white
8.24:1passpasspassPasses AAA — no fix needed.
Aaon black
2.55:1failfailfail
  • AA: use #696fc3 as the text (4.66:1)
  • AAA: use #8e92d2 as the text (7.19:1)
  • AA: or shift the background to #c2c2c2 (4.62:1)
  • AAA: or shift the background to #ededed (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 #3f459d 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

#3f459d reads as cool, modern. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #3f459d
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 #3f459d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/3f459d-9e9cc4-df8f4e-241f2d-e9eef1?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