Lagoon
Open in tool →Turquoise and teal with a sand-yellow on white — shallow tropical water; the deep teal text is the reef.
Color
#21b59a
#21b59a
hex
#21b59argb
rgb(33, 181, 154)hsl
hsl(169, 69%, 42%)oklch
oklch(0.694 0.123 176.3)Closest name: Billiard (#00af9f)Relative luminance 0.357
Colors that go with #21b59a
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 #21b59a: softer than #000 and cool enough to feel like part of the same palette.
Hot Pink #ff69b4
complementaryshippedHot Pink sits directly opposite #21b59a 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
shipped7 real palettes, including Fintech Trust and Ford's brand system put Midnight Blue beside #21b59a, as the text colour against it.
Mustard Yellow #ffdb58
shipped5 real palettes, including Diner and Crayon Box put Mustard Yellow beside #21b59a, as the accent.
Royal Blue #4169e1
shippedRoyal Blue is paired with #21b59a in 6 real palettes, including Khan Academy's brand system and Brilliant's brand system, as the accent.
Taupe #483c32
shippedTaupe is paired with #21b59a in 13 real palettes, including Resort and Chime's brand system, as the text colour against it.
Tomato #ff6347
split-complementshippedTomato is a split-complement of #21b59a: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Blue #0000ff
shipped3 real palettes, including Unity's brand system and Canva's brand system put Blue beside #21b59a, as the supporting colour.
Real palettes that use #21b59a
Tints & shades
Harmonies
Contrast
| #21b59a as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 2.58:1 | fail | fail | fail | |
Aaon black | 8.14:1 | 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 #21b59a 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
mcpConnect your agent — build around #21b59a
live endpointPoint 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.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #21b59a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/21b59a-a2bebc-d459ab-1f2a2d-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