Color

#21504c

#21504c
hex#21504c
rgbrgb(33, 80, 76)
hslhsl(175, 42%, 22%)
oklchoklch(0.397 0.052 187.8)
Closest name: darkslategray (#2f4f4f)Relative luminance 0.0658

Colors that go with #21504c

Crimson, Teal 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 →

#502124

#215034 · #213c50

#4c2150 · #504c21

Split-complementary

Open in tool →

#50213c · #503421

#342150 · #502124 · #3c5021

Contrast

#21504c as textRatioAAAA largeAAAFix
Aaon white
9.07:1passpasspassPasses AAA — no fix needed.
Aaon black
2.32:1failfailfail
  • AA: use #35827c as the text (4.64:1)
  • AAA: use #44a79e as the text (7.27:1)
  • AA: or shift the background to #b8b8b8 (4.57:1)
  • AAA: or shift the background to #e3e3e3 (7.06:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21504c as the background.

Brands using this color

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

Palettes built around it

Fonts for this mood

#21504c reads as dark, luxury, bold. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #21504c
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 #21504c and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21504c-a2bdbe-d4599f-1f282d-e9f1ed?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