Color

#1b0bcb

#1b0bcb
hex#1b0bcb
rgbrgb(27, 11, 203)
hslhsl(245, 90%, 42%)
oklchoklch(0.392 0.256 267.8)
Closest name: mediumblue (#0000cd)Relative luminance 0.0478

Colors that go with #1b0bcb

Charcoal, Crimson 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 →

#bbcb0b

#0b5bcb · #7b0bcb

#cb1b0b · #0bcb1b

Split-complementary

Open in tool →

#cb7b0b · #5bcb0b

#cb0b5b · #bbcb0b · #0bcb7b

Contrast

#1b0bcb as textRatioAAAA largeAAAFix
Aaon white
10.73:1passpasspassPasses AAA — no fix needed.
Aaon black
1.96:1failfailfail
  • AA: use #6c5ff7 as the text (4.62:1)
  • AAA: use #948bf9 as the text (7.32:1)
  • AA: or shift the background to #a8a8a8 (4.51:1)
  • AAA: or shift the background to #d1d1d1 (7.03:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b0bcb as the background.

Brands using this color

Fonts for this mood

#1b0bcb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b0bcb
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 #1b0bcb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b0bcb-a49cc4-dfa54e-261f2d-e9ecf1?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