Color

#0b40ef

#0b40ef
hex#0b40ef
rgbrgb(11, 64, 239)
hslhsl(226, 91%, 49%)
oklchoklch(0.485 0.262 264.3)
Closest name: C64 Blue (#003aff)Relative luminance 0.0997

Colors that go with #0b40ef

Charcoal, Crimson and Amber 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 →

#efba0b

#0bb2ef · #480bef

#ef0b40 · #40ef0b

Split-complementary

Open in tool →

#ef480b · #b2ef0b

#ef0bb2 · #efba0b · #0bef48

Contrast

#0b40ef as textRatioAAAA largeAAAFix
Aaon white
7.01:1passpasspassPasses AAA — no fix needed.
Aaon black
2.99:1failfailfail
  • AA: use #416bf6 as the text (4.66:1)
  • AAA: use #7291f8 as the text (7.12:1)
  • AA: or shift the background to #cfcfcf (4.5:1)
  • AAA: or shift the background to #ffffff (7.01:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #0b40ef as the background.

Brands using this color

Fonts for this mood

#0b40ef reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #0b40ef
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 #0b40ef and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/0b40ef-9ca1c4-df774e-221f2d-e9eff1?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