Color

#0a178a

#0a178a
hex#0a178a
rgbrgb(10, 23, 138)
hslhsl(234, 86%, 29%)
oklchoklch(0.31 0.182 266.3)
Closest name: darkblue (#00008b)Relative luminance 0.0251

Colors that go with #0a178a

Crimson, 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 →

#8a7d0a

#0a578a · #3d0a8a

#8a0a17 · #178a0a

Split-complementary

Open in tool →

#8a3d0a · #578a0a

#8a0a57 · #8a7d0a · #0a8a3d

Contrast

#0a178a as textRatioAAAA largeAAAFix
Aaon white
13.98:1passpasspassPasses AAA — no fix needed.
Aaon black
1.5:1failfailfail
  • AA: use #5968f3 as the text (4.7:1)
  • AAA: use #848ff6 as the text (7.24:1)
  • AA: or shift the background to #949494 (4.61:1)
  • AAA: or shift the background to #b8b8b8 (7.05:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #0a178a as the background.

Brands using this color

Fonts for this mood

#0a178a reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #0a178a
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 #0a178a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/0a178a-9d9cc4-df8a4e-241f2d-e9eef1?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