Color

#a21528

#a21528
hex#a21528
rgbrgb(162, 21, 40)
hslhsl(352, 77%, 36%)
oklchoklch(0.459 0.172 21.8)
Closest name: Bleeding Crimson (#9b1414)Relative luminance 0.0837

Colors that go with #a21528

Royal Blue, Teal and Champagne 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.

Real palettes that use #a21528

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#15a290

#a2156f · #a24915

#28a215 · #1528a2

Split-complementary

Open in tool →

#15a249 · #156fa2

#6fa215 · #15a290 · #4915a2

Contrast

#a21528 as textRatioAAAA largeAAAFix
Aaon white
7.85:1passpasspassPasses AAA — no fix needed.
Aaon black
2.67:1failfailfail
  • AA: use #e2223b as the text (4.53:1)
  • AAA: use #ec6f7f as the text (7.15:1)
  • AA: or shift the background to #c4c4c4 (4.5:1)
  • AAA: or shift the background to #f2f2f2 (7.01:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #a21528 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

#a21528 reads as warm, vivid, playful. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #a21528
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 #a21528 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/a21528-c49c9d-62cb8a-2d231f-f1e9ee?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