Color

#1b2b83

#1b2b83
hex#1b2b83
rgbrgb(27, 43, 131)
hslhsl(231, 66%, 31%)
oklchoklch(0.341 0.148 268.8)
Closest name: Below the Surface (#0a2f7c)Relative luminance 0.036

Colors that go with #1b2b83

Charcoal, Steel Blue and 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 →

#83741b

#1b5f83 · #3f1b83

#831b2b · #2b831b

Split-complementary

Open in tool →

#833f1b · #5f831b

#831b5f · #83741b · #1b833f

Contrast

#1b2b83 as textRatioAAAA largeAAAFix
Aaon white
12.21:1passpasspassPasses AAA — no fix needed.
Aaon black
1.72:1failfailfail
  • AA: use #5a6edd as the text (4.71:1)
  • AAA: use #8493e6 as the text (7.3:1)
  • AA: or shift the background to #9e9e9e (4.56:1)
  • AAA: or shift the background to #c4c4c4 (7:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b2b83 as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#1b2b83 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b2b83
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 #1b2b83 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b2b83-9c9ec4-df834e-231f2d-e9eef1?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