Color

#213b91

#213b91
hex#213b91
rgbrgb(33, 59, 145)
hslhsl(226, 63%, 35%)
oklchoklch(0.389 0.146 266.6)
Closest name: Depths of Night (#2c319b)Relative luminance 0.055

Colors that go with #213b91

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 →

#917721

#217391 · #3f2191

#91213b · #3b9121

Split-complementary

Open in tool →

#913f21 · #739121

#912173 · #917721 · #21913f

Contrast

#213b91 as textRatioAAAA largeAAAFix
Aaon white
10:1passpasspassPasses AAA — no fix needed.
Aaon black
2.1:1failfailfail
  • AA: use #5070d7 as the text (4.64:1)
  • AAA: use #7a92e1 as the text (7.03:1)
  • AA: or shift the background to #b0b0b0 (4.61:1)
  • AAA: or shift the background to #d9d9d9 (7.09:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #213b91 as the background.

Brands using this color

Palettes built around it

Fonts for this mood

#213b91 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #213b91
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 #213b91 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/213b91-9ca1c4-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