Color

#21c491

#21c491
hex#21c491
rgbrgb(33, 196, 145)
hslhsl(161, 71%, 45%)
oklchoklch(0.73 0.147 165.3)
Closest name: Bleached Olive (#55bb88)Relative luminance 0.4185

Colors that go with #21c491

Charcoal, Hot Pink 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 →

#c42155

#21c43f · #21a6c4

#9121c4 · #c49121

Split-complementary

Open in tool →

#c421a6 · #c43f21

#3f21c4 · #c42155 · #a6c421

Contrast

#21c491 as textRatioAAAA largeAAAFix
Aaon white
2.24:1failfailfail
  • AA: use #168360 as the text (4.72:1)
  • AAA: use #11644a as the text (7.13:1)
  • AA: or shift the background to #404040 (4.63:1)
  • AAA: or shift the background to #212121 (7.18:1)
Aaon black
9.37:1passpasspassPasses AAA — no fix needed.

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #21c491 as the background.

Brands using this color

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

mcpConnect your agent — build around #21c491
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 #21c491 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/21c491-a2beb8-d459bb-1f2c2d-e9f1eb?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