Learning App
Open in tool →Green, blue and orange at full saturation: the gamified-learning look, where every color is a reward.
Color
#51c81e
#51c81e
hex
#51c81ergb
rgb(81, 200, 30)hsl
hsl(102, 74%, 45%)oklch
oklch(0.736 0.222 138.9)Closest name: Lime Green (#32cd32)Relative luminance 0.4315
Colors that go with #51c81e
Blue, Charcoal and Taupe 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.
Blue #0000ff
shipped4 real palettes, including Minecraft's brand system and Spotify's brand system put Blue beside #51c81e, as the accent.
Charcoal #36454f
neutralshippedCharcoal is the body-text near-black for #51c81e: its slight blue cast keeps type crisp beside a warm colour where pure #000 looks heavy.
Taupe #483c32
shippedTaupe is paired with #51c81e in 9 real palettes, including Minecraft's brand system and Obsidian's brand system, as the lead colour.
Violet #ee82ee
complementaryViolet sits directly opposite #51c81e on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Hot Pink #ff69b4
split-complementshippedHot Pink is a split-complement of #51c81e: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Cornflower Blue #6495ed
split-complementshippedCornflower Blue is a split-complement of #51c81e: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Dark Orange #ff8c00
shippedDark Orange shows up next to #51c81e in 3 real palettes, including Learning App and Playground, as the accent.
Mustard Yellow #ffdb58
shipped3 real palettes, including Meadow and Citrus Grove put Mustard Yellow beside #51c81e, as the supporting colour.
Real palettes that use #51c81e
Tints & shades
Harmonies
Contrast
| #51c81e as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 2.18:1 | fail | fail | fail | |
Aaon black | 9.63:1 | 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 #51c81e as the background.
Brands using this color
Palettes built around it
mcpConnect your agent — build around #51c81e
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 #51c81e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/51c81e-a7bea2-6e4edf-1f2d21-eff1e9?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