Color

#210b6f

#210b6f
hex#210b6f
rgbrgb(33, 11, 111)
hslhsl(253, 82%, 24%)
oklchoklch(0.276 0.153 279.6)
Closest name: Child of the Night (#220077)Relative luminance 0.0171

Colors that go with #210b6f

Charcoal, 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 →

#5a6f0b

#0b276f · #530b6f

#6f210b · #0b6f21

Split-complementary

Open in tool →

#6f530b · #276f0b

#6f0b27 · #5a6f0b · #0b6f53

Contrast

#210b6f as textRatioAAAA largeAAAFix
Aaon white
15.65:1passpasspassPasses AAA — no fix needed.
Aaon black
1.34:1failfailfail
  • AA: use #7c5def as the text (4.67:1)
  • AAA: use #9e86f3 as the text (7.16:1)
  • AA: or shift the background to #8a8a8a (4.53:1)
  • AAA: or shift the background to #b0b0b0 (7.22:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #210b6f as the background.

Brands using this color

No public brand in the corpus uses this exact color yet. Extract a brand to add one.

Fonts for this mood

#210b6f reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #210b6f
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 #210b6f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/210b6f-a99cc4-dfb84e-281f2d-e9ebf1?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