#57A2D4

CSS

:root {
  --sub-zero: #57a2d4;
  --sub-zero-rgb: 87 162 212;
  --sub-zero-oklch: oklch(0.684 0.105 239.9);
}

.element {
  color: var(--sub-zero);
  background-color: hsl(204 59% 59%);
  border-color: oklch(0.684 0.105 239.9);
}

Tailwind CSS v4

@theme {
  --color-sub-zero: #57a2d4;
  --color-sub-zero-50: #dcfaff;
  --color-sub-zero-100: #caedff;
  --color-sub-zero-200: #addbfe;
  --color-sub-zero-300: #87bee9;
  --color-sub-zero-400: #60a7d6;
  --color-sub-zero-500: #388ec4;
  --color-sub-zero-600: #3179a6;
  --color-sub-zero-700: #276085;
  --color-sub-zero-800: #184762;
  --color-sub-zero-900: #103145;
  --color-sub-zero-950: #031d2d;
}

SCSS

$sub-zero: #57a2d4;
$sub-zero-rgb: 87, 162, 212;
$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);
}