# #51b370

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

## Values

- Hex: `#51b370`
- RGB: rgb(81, 179, 112)
- HSL: hsl(139, 39%, 51%)
- OKLCH: oklch(0.691 0.135 151.6)
- Relative luminance: 0.3516
- Nearest named color: mediumseagreen (#3cb371, Δ 1.367) — https://brandsweets.com/colors/mediumseagreen
- Moods: neutral
- Page: https://brandsweets.com/colors/51b370

## Tints & shades

- Tints (toward white): #63bb7f, #71c18a, #83c999, #95d0a8, #a6d8b6, #b5dec2, #c6e6d0, #d8eedf, #e6f4eb, #f8fcf9
- Shades (toward black): #48a365, #41955c, #3a8351, #327146, #2c633d, #245232, #1c4027, #142e1c, #0e2014, #060e09

## Harmonies

- Complementary: #b35194
- Analogous: #63b351, #51b3a1
- Triadic: #7051b3, #b37051
- Split-complementary: #a151b3, #b35163
- Tetradic: #5163b3, #b35194, #b3a151

## Colors that go with #51b370

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 text near-black for #51b370: softer than #000 and cool enough to feel like part of the same palette. Seen in: Mint Modern (https://brandsweets.com/palettes/modern#mint-modern), N26 (https://brandsweets.com/colors/brands/n26-com), Zendesk (https://brandsweets.com/colors/brands/zendesk-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 #51b370, as the supporting colour. Seen in: Meadow (https://brandsweets.com/palettes/light#meadow), Citrus Grove (https://brandsweets.com/palettes/warm#citrus-grove), Diner (https://brandsweets.com/palettes/vivid#diner), Fresh Juice (https://brandsweets.com/palettes/playful#fresh-juice). — https://brandsweets.com/colors/mustard
- **Royal Blue** #4169e1 [pool] — Royal Blue is paired with #51b370 in 5 real palettes, including Khan Academy's brand system and Brilliant's brand system, as the accent. Seen in: Khan Academy (https://brandsweets.com/colors/brands/khanacademy-org), Brilliant (https://brandsweets.com/colors/brands/brilliant-org), Console Light (https://brandsweets.com/palettes/technical#console-light), Telehealth (https://brandsweets.com/palettes/modern#telehealth). — https://brandsweets.com/colors/royalblue
- **Taupe** #483c32 [pool] — Taupe is paired with #51b370 in 15 real palettes, including Undergrowth and Chime's brand system, as the surface under it. Seen in: Undergrowth (https://brandsweets.com/palettes/dark#undergrowth), Chime (https://brandsweets.com/colors/brands/chime-com), Meadow (https://brandsweets.com/palettes/light#meadow), Obsidian (https://brandsweets.com/colors/brands/obsidian-md). — https://brandsweets.com/colors/taupe
- **Orchid** #da70d6 [harmony: complementary] — Orchid sits directly opposite #51b370 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/orchid
- **Medium Purple** #9370db [harmony, pool: split] — Medium Purple is a split-complement of #51b370: 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 Unity's brand system and Spotify's brand system put Blue beside #51b370, as the supporting colour. Seen in: Unity (https://brandsweets.com/colors/brands/unity-com), Spotify (https://brandsweets.com/colors/brands/spotify), Minecraft (https://brandsweets.com/colors/brands/minecraft-net). — https://brandsweets.com/colors/blue
- **Cornflower Blue** #6495ed [harmony, pool: triadic] — Cornflower Blue completes a triad with #51b370 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Terminal (https://brandsweets.com/palettes/technical#terminal), Spotify (https://brandsweets.com/colors/brands/spotify). — https://brandsweets.com/colors/cornflowerblue

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

- On white (#ffffff): 2.61:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #3a8351 (4.62:1); AA: background → #363636 (4.62:1); AAA: text → #2c633d (7.1:1); AAA: background → #141414 (7.05:1)
- On black (#000000): 8.03:1 — AA pass, AA-large pass, AAA pass

## Brands using this color

- **DuckDuckGo** — accent #38b26a (Δ 1.977) — https://brandsweets.com/colors/brands/duckduckgo-com

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/51b370-a2beae-c059d4-1f2d2a-ebf1e9?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: "#51b370" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.