Color

#1b3d64

#1b3d64
hex#1b3d64
rgbrgb(27, 61, 100)
hslhsl(212, 57%, 25%)
oklchoklch(0.356 0.079 253.6)
Closest name: Aegean Blue (#1b416f)Relative luminance 0.0449

Colors that go with #1b3d64

Firebrick, Sea Green and Teal 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 →

#64421b

#1b6264 · #1e1b64

#641b3d · #3d641b

Split-complementary

Open in tool →

#641e1b · #62641b

#641b62 · #64421b · #1b641e

Contrast

#1b3d64 as textRatioAAAA largeAAAFix
Aaon white
11.06:1passpasspassPasses AAA — no fix needed.
Aaon black
1.9:1failfailfail
  • AA: use #3576c0 as the text (4.5:1)
  • AAA: use #679ad5 as the text (7.16:1)
  • AA: or shift the background to #a6a6a6 (4.54:1)
  • AAA: or shift the background to #cfcfcf (7.1:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b3d64 as the background.

Brands using this color

Fonts for this mood

#1b3d64 reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b3d64
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 #1b3d64 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b3d64-9caac4-df564e-1f202d-e9f1f1?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