Color

#123f4e

#123f4e
hex#123f4e
rgbrgb(18, 63, 78)
hslhsl(195, 63%, 19%)
oklchoklch(0.345 0.054 224.1)
Closest name: Cold and Dark (#154250)Relative luminance 0.0423

Colors that go with #123f4e

Crimson, Denim 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 →

#4f2112

#124f40 · #12214f

#4f1240 · #404f12

Split-complementary

Open in tool →

#4f1221 · #4f4012

#40124f · #4f2112 · #214f12

Contrast

#123f4e as textRatioAAAA largeAAAFix
Aaon white
11.37:1passpasspassPasses AAA — no fix needed.
Aaon black
1.85:1failfailfail
  • AA: use #247f9e as the text (4.6:1)
  • AAA: use #2da1c8 as the text (7.04:1)
  • AA: or shift the background to #a3a3a3 (4.51:1)
  • AAA: or shift the background to #cccccc (7.08:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #123f4e as the background.

Brands using this color

Fonts for this mood

#123f4e reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #123f4e
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 #123f4e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/123f4e-9cb5c4-df4e70-1f242d-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