# #21b557

A color — vivid. Deterministic analysis from BrandSweets (no inference).

## Values

- Hex: `#21b557`
- RGB: rgb(33, 181, 87)
- HSL: hsl(142, 69%, 42%)
- OKLCH: oklch(0.679 0.179 149.7)
- Relative luminance: 0.3406
- Nearest named color: Intoxicate (#11bb55, Δ 1.82) — https://brandsweets.com/colors/intoxicate
- Moods: vivid
- Page: https://brandsweets.com/colors/21b557

## Tints & shades

- Tints (toward white): #26cf64, #34da71, #4edf83, #64e392, #7ee7a4, #98ecb7, #adf0c6, #c7f5d8, #ddf9e7, #f6fdf9
- Shades (toward black): #1ea44f, #1b9347, #198641, #157438, #126330, #0f5228, #0c411f, #093419, #062211, #031108

## Harmonies

- Complementary: #b5217f
- Analogous: #35b521, #21b5a1
- Triadic: #5721b5, #b55721
- Split-complementary: #a121b5, #b52135
- Tetradic: #2135b5, #b5217f, #b5a121

## Colors that go with #21b557

Named partners (harmony on the OKLCH wheel, co-occurrence in curated palettes and brand systems, and the neutrals that carry it), best first:

- **Charcoal** #36454f [role, pool] — Charcoal is the body-text near-black for #21b557: its slight blue cast keeps type crisp beside a warm colour where pure #000 looks heavy. Seen in: Mint Modern (https://brandsweets.com/palettes/modern#mint-modern), Zendesk (https://brandsweets.com/colors/brands/zendesk-com), N26 (https://brandsweets.com/colors/brands/n26-com), Lagoon (https://brandsweets.com/palettes/vivid#lagoon). — https://brandsweets.com/colors/charcoal
- **Mustard Yellow** #ffdb58 [pool] — 4 real palettes, including Meadow and Citrus Grove put Mustard Yellow beside #21b557, as the supporting colour. Seen in: Meadow (https://brandsweets.com/palettes/light#meadow), Citrus Grove (https://brandsweets.com/palettes/warm#citrus-grove), Fresh Juice (https://brandsweets.com/palettes/playful#fresh-juice), Diner (https://brandsweets.com/palettes/vivid#diner). — https://brandsweets.com/colors/mustard
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #21b557 in 5 real palettes, including Console Light and Telehealth, as the lead colour. Seen in: Console Light (https://brandsweets.com/palettes/technical#console-light), Telehealth (https://brandsweets.com/palettes/modern#telehealth), Brilliant (https://brandsweets.com/colors/brands/brilliant-org), Khan Academy (https://brandsweets.com/colors/brands/khanacademy-org). — https://brandsweets.com/colors/royalblue
- **Taupe** #483c32 [pool] — Taupe is paired with #21b557 in 8 real palettes, including Obsidian's brand system and Chime's brand system, as the text colour against it. Seen in: Obsidian (https://brandsweets.com/colors/brands/obsidian-md), Chime (https://brandsweets.com/colors/brands/chime-com), Meadow (https://brandsweets.com/palettes/light#meadow), Minecraft (https://brandsweets.com/colors/brands/minecraft-net). — https://brandsweets.com/colors/taupe
- **Fuchsia** #ff00ff [harmony: complementary] — Fuchsia sits directly opposite #21b557 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. — https://brandsweets.com/colors/fuchsia
- **Hot Pink** #ff69b4 [harmony, pool: split] — Hot Pink is a split-complement of #21b557: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Terminal (https://brandsweets.com/palettes/technical#terminal). — https://brandsweets.com/colors/hotpink
- **Medium Purple** #9370db [harmony, pool: split] — Medium Purple is a split-complement of #21b557: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Obsidian (https://brandsweets.com/colors/brands/obsidian-md), Next.js (https://brandsweets.com/colors/brands/nextjs-org). — https://brandsweets.com/colors/mediumpurple
- **Blue** #0000ff [pool] — 3 real palettes, including Spotify's brand system and Unity's brand system put Blue beside #21b557, as the accent. Seen in: Spotify (https://brandsweets.com/colors/brands/spotify), Unity (https://brandsweets.com/colors/brands/unity-com), Minecraft (https://brandsweets.com/colors/brands/minecraft-net). — https://brandsweets.com/colors/blue

## Contrast (WCAG 2.x, as text)

- On white (#ffffff): 2.69:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #198641 (4.64:1); AA: background → #333333 (4.7:1); AAA: text → #126330 (7.36:1); AAA: background → #0f0f0f (7.13:1)
- On black (#000000): 7.81:1 — AA pass, AA-large pass, AAA pass

## Brands using this color

- **Spotify** — primary #1db954 (Δ 1.3) — https://brandsweets.com/colors/brands/spotify

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/21b557-a2beaf-c659d4-1f2d2a-eaf1e9?lock=0&style=vibrant
(Humans lock/regenerate in the tool; the URL is the state — read `lock=` back to see what they kept.)

## Connect an agent

Point any MCP client at the BrandSweets colors endpoint for the same engine:

- Endpoint: https://mcp.brandsweets.com/colors/mcp
- Tools: `analyze_color` (e.g. `analyze_color({ color: "#21b557" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.