#4DA3D3

CSS

:root {
  --sub-zero: #4da3d3;
  --sub-zero-rgb: 77 163 211;
  --sub-zero-oklch: oklch(0.682 0.109 235.9);
}

.element {
  color: var(--sub-zero);
  background-color: hsl(201 60% 56%);
  border-color: oklch(0.682 0.109 235.9);
}

Tailwind CSS v4

@theme {
  --color-sub-zero: #4da3d3;
  --color-sub-zero-50: #d9fbff;
  --color-sub-zero-100: #c7eeff;
  --color-sub-zero-200: #a9dcfe;
  --color-sub-zero-300: #81c0e9;
  --color-sub-zero-400: #58a8d6;
  --color-sub-zero-500: #2890c4;
  --color-sub-zero-600: #257aa6;
  --color-sub-zero-700: #1e6285;
  --color-sub-zero-800: #104862;
  --color-sub-zero-900: #0b3245;
  --color-sub-zero-950: #001e2d;
}

SCSS

$sub-zero: #4da3d3;
$sub-zero-rgb: 77, 163, 211;
$sub-zero-light: mix(#fff, $sub-zero, 20%);
$sub-zero-dark: mix(#000, $sub-zero, 20%);

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