Color

#0f4eb3

#0f4eb3
hex#0f4eb3
rgbrgb(15, 78, 179)
hslhsl(217, 85%, 38%)
oklchoklch(0.452 0.172 260.3)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0881

Colors that go with #0f4eb3

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 →

#b3740f

#0fa0b3 · #220fb3

#b30f4e · #4eb30f

Split-complementary

Open in tool →

#b3220f · #a0b30f

#b30fa0 · #b3740f · #0fb322

Contrast

#0f4eb3 as textRatioAAAA largeAAAFix
Aaon white
7.61:1passpasspassPasses AAA — no fix needed.
Aaon black
2.76:1failfailfail
  • AA: use #216fed as the text (4.56:1)
  • AAA: use #5f97f2 as the text (7.2:1)
  • AA: or shift the background to #c9c9c9 (4.59:1)
  • AAA: or shift the background to #f7f7f7 (7.1:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #0f4eb3 as the background.

Brands using this color

Fonts for this mood

#0f4eb3 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #0f4eb3
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 #0f4eb3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/0f4eb3-9ca7c4-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