Color

#4001df

#4001df
hex#4001df
rgbrgb(64, 1, 223)
hslhsl(257, 99%, 44%)
oklchoklch(0.435 0.269 276.8)
Closest name: Busty Blue (#3300cc)Relative luminance 0.0644

Colors that go with #4001df

Charcoal, Cobalt Blue and Cornflower 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 →

#a0df01

#0131df · #af01df

#df4001 · #01df40

Split-complementary

Open in tool →

#dfaf01 · #31df01

#df0131 · #a0df01 · #01dfaf

Contrast

#4001df as textRatioAAAA largeAAAFix
Aaon white
9.18:1passpasspassPasses AAA — no fix needed.
Aaon black
2.29:1failfailfail
  • AA: use #8352fe as the text (4.6:1)
  • AAA: use #a480fe as the text (7.1:1)
  • AA: or shift the background to #b8b8b8 (4.63:1)
  • AAA: or shift the background to #e3e3e3 (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #4001df 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

#4001df reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #4001df
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 #4001df and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/4001df-ac9cc4-dfc24e-291f2d-e9ebf1?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