Color
#21b09d
#21b09drgb(33, 176, 157)hsl(172, 68%, 41%)oklch(0.682 0.117 181.1)Colors that go with #21b09d
Charcoal, Hot Pink and Midnight 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.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #21b09d: softer than #000 and cool enough to feel like part of the same palette.
Hot Pink #ff69b4
complementaryshippedHot Pink sits directly opposite #21b09d on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Midnight Blue #191970
shipped6 real palettes, including Fintech Trust and Ford's brand system put Midnight Blue beside #21b09d, as the text colour against it.
Mustard Yellow #ffdb58
shipped4 real palettes, including Diner and Lido put Mustard Yellow beside #21b09d, as the accent.
Royal Blue #4169e1
shippedRoyal Blue is paired with #21b09d in 7 real palettes, including Khan Academy's brand system and Brilliant's brand system, as the accent.
Taupe #483c32
shippedTaupe is paired with #21b09d in 12 real palettes, including Resort and Undergrowth, as the text colour against it.
Tomato #ff6347
split-complementshippedTomato is a split-complement of #21b09d: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Blush Pink #e8b4b8
shipped3 real palettes, including Garden Wedding and Rain Garden put Blush Pink beside #21b09d, as the supporting colour.
Real palettes that use #21b09d
Tints & shades
Harmonies
Contrast
| #21b09d as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 2.71:1 | fail | fail | fail | |
Aaon black | 7.76:1 | pass | pass | pass | Passes 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 #21b09d as the background.
Brands using this color
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.
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
›analyze #21b09d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/21b09d-a2bebe-d459a5-1f292d-e9f1ec?lock=0&style=vibrantWant the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.
Machine-readable: color.md