Color

#1b645a

#1b645a
hex#1b645a
rgbrgb(27, 100, 90)
hslhsl(172, 57%, 25%)
oklchoklch(0.456 0.072 182)
Closest name: Mosque (#005f5b)Relative luminance 0.1009

Colors that go with #1b645a

Cadet Blue, Champagne and Copper 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.

Real palettes that use #1b645a

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#641b25

#1b6436 · #1b4964

#5a1b64 · #645a1b

Split-complementary

Open in tool →

#641b49 · #64361b

#361b64 · #641b25 · #49641b

Contrast

#1b645a as textRatioAAAA largeAAAFix
Aaon white
6.96:1passpassfail
  • AAA: use #1a6057 as the text (7.36:1)
Aaon black
3.02:1failpassfail
  • AA: use #248477 as the text (4.64:1)
  • AAA: use #2ea898 as the text (7.17:1)
  • AA: or shift the background to #d1d1d1 (4.56:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b645a as the background.

Brands using this color

Fonts for this mood

#1b645a reads as dark, luxury, bold. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b645a
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 #1b645a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b645a-a2bebe-d459a5-1f292d-e9f1ec?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