Color

#172a78

#172a78
hex#172a78
rgbrgb(23, 42, 120)
hslhsl(228, 68%, 28%)
oklchoklch(0.326 0.135 267.5)
Closest name: Below the Surface (#0a2f7c)Relative luminance 0.0319

Colors that go with #172a78

Charcoal, Steel Blue and 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 →

#786517

#175b78 · #341778

#78172a · #2a7817

Split-complementary

Open in tool →

#783417 · #5b7817

#78175b · #786517 · #177834

Contrast

#172a78 as textRatioAAAA largeAAAFix
Aaon white
12.81:1passpasspassPasses AAA — no fix needed.
Aaon black
1.64:1failfailfail
  • AA: use #4f6cde as the text (4.53:1)
  • AAA: use #7e93e7 as the text (7.21:1)
  • AA: or shift the background to #9c9c9c (4.67:1)
  • AAA: or shift the background to #c2c2c2 (7.19:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #172a78 as the background.

Brands using this color

Fonts for this mood

#172a78 reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #172a78
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 #172a78 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/172a78-9c9fc4-df7c4e-231f2d-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