Color

#183a3f

#183a3f
hex#183a3f
rgbrgb(24, 58, 63)
hslhsl(188, 45%, 17%)
oklchoklch(0.325 0.04 208.1)
Closest name: Royal Neptune (#1c3b42)Relative luminance 0.0358

Tints & shades

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

Harmonies

Complementary

Open in tool →

#3f1d18

#183f31 · #18263f

#3f183a · #3a3f18

Split-complementary

Open in tool →

#3f1826 · #3f3118

#31183f · #3f1d18 · #263f18

Contrast

#183a3f as textRatioAAAA largeAAAFix
Aaon white
12.24:1passpasspassPasses AAA — no fix needed.
Aaon black
1.72:1failfailfail
  • AA: use #35818d as the text (4.68:1)
  • AAA: use #43a3b1 as the text (7.11:1)
  • AA: or shift the background to #9e9e9e (4.57:1)
  • AAA: or shift the background to #c4c4c4 (7.02:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #183a3f 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

#183a3f reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #183a3f
live endpoint

Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #183a3f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/183a3f-a2b7be-df4e81-1f252d-e9f1ee?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