Poisonous
#55ff11
Ominous, sickly chartreuse for high-alert UI
About Poisonous
Poisonous is the green you notice as soon as it hits a dark panel, but it reads as a little more aggressive than Neon Green. It has that punchy, medium-light glow with a saturated, almost acidic bite, yet it's not yellow-leaning like Acid. It also doesn't feel "grown" like Fertility Green, which sits steadier and more natural.
I use Poisonous when I need attention without flipping to warning red: status alerts in industrial HMI screens, chemical and lab workflow monitors, and quality-control systems where you want a clear "stop and look" moment that still stays green-family consistent. Compared to Electric Laser Lime, it's less cool and laser-clean, more forward and insistent, so it lands closer to hazard-highlighting than pure active-state signal.
Quirk: on very busy interfaces it can bully nearby UI tones. Pair it with deep greens or charcoal so the intent stays sharp, not frantic.
Code snippets
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Contrast checker
WCAG 2.1 contrast ratios. AA requires 4.5:1 for normal text, 3:1 for large. AAA requires 7:1 / 4.5:1.
On White #ffffff
On Gray 100 #f5f5f5
On Gray 900 #18181b
On Black #000000
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