Color

#100d9b

#100d9b
hex#100d9b
rgbrgb(16, 13, 155)
hslhsl(241, 85%, 33%)
oklchoklch(0.325 0.207 267.3)
Closest name: Everlasting Night (#000099)Relative luminance 0.0276

Colors that go with #100d9b

Crimson, Steel Blue and Cobalt 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 →

#999c0d

#0d529c · #570d9c

#9c0f0d · #0d9c0f

Split-complementary

Open in tool →

#9c570d · #529c0d

#9c0d52 · #999c0d · #0d9c57

Contrast

#100d9b as textRatioAAAA largeAAAFix
Aaon white
13.52:1passpasspassPasses AAA — no fix needed.
Aaon black
1.55:1failfailfail
  • AA: use #6663f2 as the text (4.63:1)
  • AAA: use #908ef6 as the text (7.39:1)
  • AA: or shift the background to #969696 (4.57:1)
  • AAA: or shift the background to #bdbdbd (7.2:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #100d9b as the background.

Brands using this color

Fonts for this mood

#100d9b reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #100d9b
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 #100d9b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/100d9b-a19cc4-df9b4e-261f2d-e9edf1?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