Color

#21515e

#21515e
hex#21515e
rgbrgb(33, 81, 94)
hslhsl(193, 48%, 25%)
oklchoklch(0.408 0.056 218.4)
Closest name: Raging Thunderstorm (#004f63)Relative luminance 0.0702

Colors that go with #21515e

Crimson, Steel Blue and Teal 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 →

#5e2e21

#215e4d · #21325e

#5e2151 · #515e21

Split-complementary

Open in tool →

#5e2132 · #5e4d21

#4d215e · #5e2e21 · #325e21

Contrast

#21515e as textRatioAAAA largeAAAFix
Aaon white
8.74:1passpasspassPasses AAA — no fix needed.
Aaon black
2.4:1failfailfail
  • AA: use #347f93 as the text (4.6:1)
  • AAA: use #42a2bd as the text (7.13:1)
  • AA: or shift the background to #bababa (4.5:1)
  • AAA: or shift the background to #e6e6e6 (7:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21515e as the background.

Brands using this color

Fonts for this mood

#21515e reads as cool, dark, luxury. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #21515e
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 #21515e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21515e-a2b5be-df4e75-1f242d-e9f1ef?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