#54A3CE

CSS

:root {
  --sub-zero: #54a3ce;
  --sub-zero-rgb: 84 163 206;
  --sub-zero-oklch: oklch(0.683 0.1 234.7);
}

.element {
  color: var(--sub-zero);
  background-color: hsl(201 55% 57%);
  border-color: oklch(0.683 0.1 234.7);
}

Tailwind CSS v4

@theme {
  --color-sub-zero: #54a3ce;
  --color-sub-zero-50: #dbfaff;
  --color-sub-zero-100: #c9eeff;
  --color-sub-zero-200: #acdcfa;
  --color-sub-zero-300: #85c0e4;
  --color-sub-zero-400: #5ea8d1;
  --color-sub-zero-500: #3390bf;
  --color-sub-zero-600: #2e7aa1;
  --color-sub-zero-700: #246281;
  --color-sub-zero-800: #16485f;
  --color-sub-zero-900: #0f3243;
  --color-sub-zero-950: #021e2b;
}

SCSS

$sub-zero: #54a3ce;
$sub-zero-rgb: 84, 163, 206;
$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);
}