Color

#123b63

#123b63
hex#123b63
rgbrgb(18, 59, 99)
hslhsl(210, 69%, 23%)
oklchoklch(0.346 0.083 251.1)
Closest name: Aegean Blue (#1b416f)Relative luminance 0.0416

Colors that go with #123b63

Crimson, 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 →

#633b12

#126363 · #121263

#63123b · #3b6312

Split-complementary

Open in tool →

#631212 · #636312

#631263 · #633b12 · #126312

Contrast

#123b63 as textRatioAAAA largeAAAFix
Aaon white
11.47:1passpasspassPasses AAA — no fix needed.
Aaon black
1.83:1failfailfail
  • AA: use #2578cb as the text (4.63:1)
  • AAA: use #579ce0 as the text (7.24:1)
  • AA: or shift the background to #a3a3a3 (4.55:1)
  • AAA: or shift the background to #cccccc (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 #123b63 as the background.

Brands using this color

Fonts for this mood

#123b63 reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #123b63
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 #123b63 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/123b63-9cabc4-df514e-1f202d-e9f1f1?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