#54A3D0

CSS

:root {
  --sub-zero: #54a3d0;
  --sub-zero-rgb: 84 163 208;
  --sub-zero-oklch: oklch(0.684 0.102 235.9);
}

.element {
  color: var(--sub-zero);
  background-color: hsl(202 57% 57%);
  border-color: oklch(0.684 0.102 235.9);
}

Tailwind CSS v4

@theme {
  --color-sub-zero: #54a3d0;
  --color-sub-zero-50: #dbfaff;
  --color-sub-zero-100: #c9eeff;
  --color-sub-zero-200: #acdbfb;
  --color-sub-zero-300: #85bfe6;
  --color-sub-zero-400: #5ea8d3;
  --color-sub-zero-500: #3390c0;
  --color-sub-zero-600: #2d7aa2;
  --color-sub-zero-700: #246182;
  --color-sub-zero-800: #164860;
  --color-sub-zero-900: #0e3243;
  --color-sub-zero-950: #021e2c;
}

SCSS

$sub-zero: #54a3d0;
$sub-zero-rgb: 84, 163, 208;
$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);
}