Color

#1b375a

#1b375a
hex#1b375a
rgbrgb(27, 55, 90)
hslhsl(213, 54%, 23%)
oklchoklch(0.334 0.071 255)
Closest name: Beyond the Stars (#0a3251)Relative luminance 0.037

Colors that go with #1b375a

Sea Green, Teal and Sienna 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 →

#5a3e1b

#1b575a · #1e1b5a

#5a1b37 · #375a1b

Split-complementary

Open in tool →

#5a1e1b · #575a1b

#5a1b57 · #5a3e1b · #1b5a1e

Contrast

#1b375a as textRatioAAAA largeAAAFix
Aaon white
12.06:1passpasspassPasses AAA — no fix needed.
Aaon black
1.74:1failfailfail
  • AA: use #3976c0 as the text (4.53:1)
  • AAA: use #6a99d2 as the text (7.1:1)
  • AA: or shift the background to #9e9e9e (4.5:1)
  • AAA: or shift the background to #c7c7c7 (7.14:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #1b375a as the background.

Brands using this color

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

Palettes built around it

Fonts for this mood

#1b375a reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #1b375a
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 #1b375a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/1b375a-9ca9c4-df584e-1f202d-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