Terminal
Open in tool →Green for success, blue for links, pink for emphasis — the dark-mode developer family, tuned to sit on near-black without glare.
Color
#40bf51
#40bf51
hex
#40bf51rgb
rgb(64, 191, 81)hsl
hsl(128, 50%, 50%)oklch
oklch(0.711 0.187 145.5)Closest name: Intoxicate (#11bb55)Relative luminance 0.3895
Colors that go with #40bf51
Charcoal, Royal Blue 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.
Charcoal #36454f
neutralshippedCharcoal is the body-text near-black for #40bf51: its slight blue cast keeps type crisp beside a warm colour where pure #000 looks heavy.
Royal Blue #4169e1
shippedRoyal Blue is paired with #40bf51 in 5 real palettes, including Brilliant's brand system and Khan Academy's brand system, as the accent.
Taupe #483c32
shippedTaupe is paired with #40bf51 in 9 real palettes, including Obsidian's brand system and Meadow, as the text colour against it.
Orchid #da70d6
complementaryOrchid sits directly opposite #40bf51 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 #40bf51: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Blue #0000ff
shipped3 real palettes, including Spotify's brand system and Minecraft's brand system put Blue beside #40bf51, as the accent.
Cornflower Blue #6495ed
triadicshippedCornflower Blue completes a triad with #40bf51 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Dark Olive Green #556b2f
shippedDark Olive Green shows up next to #40bf51 in 3 real palettes, including Undergrowth and Forest Floor, as the supporting colour.
Real palettes that use #40bf51
Tints & shades
Harmonies
Contrast
| #40bf51 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 2.39:1 | fail | fail | fail | |
Aaon black | 8.79:1 | 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 #40bf51 as the background.
Brands using this color
Palettes built around it
mcpConnect your agent — build around #40bf51
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 #40bf51 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/40bf51-a2bea9-ac4edf-1f2d27-ecf1e9?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