Color

#1b53bb

#1b53bb
hex#1b53bb
rgbrgb(27, 83, 187)
hslhsl(219, 75%, 42%)
oklchoklch(0.472 0.174 261.4)
Closest name: Denim (#1560bd)Relative luminance 0.1001

Colors that go with #1b53bb

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 →

#bb831b

#1ba3bb · #331bbb

#bb1b53 · #53bb1b

Split-complementary

Open in tool →

#bb331b · #a3bb1b

#bb1ba3 · #bb831b · #1bbb33

Contrast

#1b53bb as textRatioAAAA largeAAAFix
Aaon white
7:1passpassfail
  • AAA: use #1a51b7 as the text (7.23:1)
Aaon black
3:1failpassfail
  • AA: use #326fe2 as the text (4.51:1)
  • AAA: use #6795e9 as the text (7.05:1)
  • AA: or shift the background to #d1d1d1 (4.58:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b53bb as the background.

Brands using this color

Fonts for this mood

#1b53bb reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b53bb
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 #1b53bb and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b53bb-9ca5c4-df664e-211f2d-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