Color

#1b4eac

#1b4eac
hex#1b4eac
rgbrgb(27, 78, 172)
hslhsl(219, 73%, 39%)
oklchoklch(0.449 0.16 261.3)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0866

Colors that go with #1b4eac

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 →

#ac791b

#1b96ac · #311bac

#ac1b4e · #4eac1b

Split-complementary

Open in tool →

#ac311b · #96ac1b

#ac1b96 · #ac791b · #1bac31

Contrast

#1b4eac as textRatioAAAA largeAAAFix
Aaon white
7.69:1passpasspassPasses AAA — no fix needed.
Aaon black
2.73:1failfailfail
  • AA: use #3470df as the text (4.53:1)
  • AAA: use #6995e8 as the text (7.06:1)
  • AA: or shift the background to #c7c7c7 (4.55:1)
  • AAA: or shift the background to #f5f5f5 (7.05:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b4eac as the background.

Brands using this color

Fonts for this mood

#1b4eac reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b4eac
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 #1b4eac and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b4eac-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