Color

#123fa1

#123fa1
hex#123fa1
rgbrgb(18, 63, 161)
hslhsl(221, 80%, 35%)
oklchoklch(0.406 0.166 262.8)
Closest name: Cobalt Blue (#0047ab)Relative luminance 0.0626

Colors that go with #123fa1

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 →

#a17312

#1286a1 · #2c12a1

#a1123f · #3fa112

Split-complementary

Open in tool →

#a12c12 · #86a112

#a11286 · #a17312 · #12a12c

Contrast

#123fa1 as textRatioAAAA largeAAAFix
Aaon white
9.33:1passpasspassPasses AAA — no fix needed.
Aaon black
2.25:1failfailfail
  • AA: use #356ee9 as the text (4.56:1)
  • AAA: use #6c95ef as the text (7.18:1)
  • AA: or shift the background to #b5b5b5 (4.55:1)
  • AAA: or shift the background to #e0e0e0 (7.07:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #123fa1 as the background.

Brands using this color

Fonts for this mood

#123fa1 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #123fa1
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 #123fa1 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/123fa1-9ca4c4-df6b4e-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