Color

#21336e

#21336e
hex#21336e
rgbrgb(33, 51, 110)
hslhsl(226, 54%, 28%)
oklchoklch(0.342 0.105 267.8)
Closest name: Atlantic Navy (#13336f)Relative luminance 0.0382

Colors that go with #21336e

Steel Blue, Blue and Cadet 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 →

#6e5c21

#21596e · #35216e

#6e2133 · #336e21

Split-complementary

Open in tool →

#6e3521 · #596e21

#6e2159 · #6e5c21 · #216e35

Contrast

#21336e as textRatioAAAA largeAAAFix
Aaon white
11.91:1passpasspassPasses AAA — no fix needed.
Aaon black
1.76:1failfailfail
  • AA: use #5672cd as the text (4.68:1)
  • AAA: use #7d93d8 as the text (7.04:1)
  • AA: or shift the background to #a1a1a1 (4.61:1)
  • AAA: or shift the background to #c7c7c7 (7.04:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21336e as the background.

Brands using this color

Fonts for this mood

#21336e reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #21336e
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 #21336e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21336e-9ca1c4-df774e-221f2d-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