Neon Blue

CSS

:root {
  --neon-blue: #04d9ff;
  --neon-blue-rgb: 4 217 255;
  --neon-blue-oklch: oklch(0.816 0.145 216.6);
}

.element {
  color: var(--neon-blue);
  background-color: hsl(189 100% 51%);
  border-color: oklch(0.816 0.145 216.6);
}

Tailwind CSS v4

@theme {
  --color-neon-blue: #04d9ff;
  --color-neon-blue-50: #c7ffff;
  --color-neon-blue-100: #b1f4ff;
  --color-neon-blue-200: #89e4fe;
  --color-neon-blue-300: #4ec9e9;
  --color-neon-blue-400: #00b2d5;
  --color-neon-blue-500: #009bc3;
  --color-neon-blue-600: #0083a5;
  --color-neon-blue-700: #006984;
  --color-neon-blue-800: #004e61;
  --color-neon-blue-900: #003644;
  --color-neon-blue-950: #00212c;
}

SCSS

$neon-blue: #04d9ff;
$neon-blue-rgb: 4, 217, 255;
$neon-blue-light: mix(#fff, $neon-blue, 20%);
$neon-blue-dark: mix(#000, $neon-blue, 20%);

.element {
  color: $neon-blue;
  box-shadow: 0 0 0 2px rgba($neon-blue, 0.35);
}