Color

#123dab

#123dab
hex#123dab
rgbrgb(18, 61, 171)
hslhsl(223, 81%, 37%)
oklchoklch(0.411 0.182 263.8)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0641

Colors that go with #123dab

Charcoal, Crimson and Steel Blue 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 →

#ab7f12

#128aab · #3312ab

#ab123d · #3dab12

Split-complementary

Open in tool →

#ab3312 · #8aab12

#ab128a · #ab7f12 · #12ab33

Contrast

#123dab as textRatioAAAA largeAAAFix
Aaon white
9.21:1passpasspassPasses AAA — no fix needed.
Aaon black
2.28:1failfailfail
  • AA: use #3d6eeb as the text (4.63:1)
  • AAA: use #7094f0 as the text (7.18:1)
  • AA: or shift the background to #b8b8b8 (4.64:1)
  • AAA: or shift the background to #e3e3e3 (7.17:1)

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

Brands using this color

Palettes built around it

Fonts for this mood

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

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

tool url/palettes/new/123dab-9ca3c4-df704e-211f2d-e9eff1?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