Color

#0b3cb7

#0b3cb7
hex#0b3cb7
rgbrgb(11, 60, 183)
hslhsl(223, 89%, 38%)
oklchoklch(0.42 0.199 263.5)
Closest name: Blue Hour (#0034ab)Relative luminance 0.0672

Colors that go with #0b3cb7

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 →

#b7860b

#0b92b7 · #300bb7

#b70b3c · #3cb70b

Split-complementary

Open in tool →

#b7300b · #92b70b

#b70b92 · #b7860b · #0bb730

Contrast

#0b3cb7 as textRatioAAAA largeAAAFix
Aaon white
8.96:1passpasspassPasses AAA — no fix needed.
Aaon black
2.34:1failfailfail
  • AA: use #356bf3 as the text (4.55:1)
  • AAA: use #6e95f7 as the text (7.31:1)
  • AA: or shift the background to #b8b8b8 (4.52:1)
  • AAA: or shift the background to #e6e6e6 (7.18:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #0b3cb7 as the background.

Brands using this color

Fonts for this mood

#0b3cb7 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #0b3cb7
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 #0b3cb7 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/0b3cb7-9ca3c4-df704e-211f2d-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