Color

#183b43

#183b43
hex#183b43
rgbrgb(24, 59, 67)
hslhsl(191, 47%, 18%)
oklchoklch(0.33 0.043 214.8)
Closest name: Royal Neptune (#1c3b42)Relative luminance 0.0373

Colors that go with #183b43

Sienna, Steel Blue 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 →

#432018

#184336 · #182643

#43183c · #3c4318

Split-complementary

Open in tool →

#431826 · #433618

#361843 · #432018 · #264318

Contrast

#183b43 as textRatioAAAA largeAAAFix
Aaon white
12.03:1passpasspassPasses AAA — no fix needed.
Aaon black
1.75:1failfailfail
  • AA: use #337e8e as the text (4.52:1)
  • AAA: use #42a2b8 as the text (7.09:1)
  • AA: or shift the background to #a1a1a1 (4.66:1)
  • AAA: or shift the background to #c7c7c7 (7.12:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183b43 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

#183b43 reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183b43
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 #183b43 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183b43-a2b6be-df4e7a-1f252d-e9f1ef?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