Color

#0b4bb1

#0b4bb1
hex#0b4bb1
rgbrgb(11, 75, 177)
hslhsl(217, 88%, 37%)
oklchoklch(0.444 0.174 260.4)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0828

Colors that go with #0b4bb1

Charcoal, Crimson 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 →

#b1720b

#0b9eb1 · #1f0bb1

#b10b4b · #4bb10b

Split-complementary

Open in tool →

#b11f0b · #9eb10b

#b10b9e · #b1720b · #0bb11f

Contrast

#0b4bb1 as textRatioAAAA largeAAAFix
Aaon white
7.91:1passpasspassPasses AAA — no fix needed.
Aaon black
2.66:1failfailfail
  • AA: use #1e6ff1 as the text (4.6:1)
  • AAA: use #5c96f5 as the text (7.14:1)
  • AA: or shift the background to #c4c4c4 (4.53:1)
  • AAA: or shift the background to #f2f2f2 (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #0b4bb1 as the background.

Brands using this color

Fonts for this mood

#0b4bb1 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #0b4bb1
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 #0b4bb1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/0b4bb1-9ca7c4-df624e-201f2d-e9f0f1?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