#71A0BF

CSS

:root {
  --wandering-river: #71a0bf;
  --wandering-river-rgb: 113 160 191;
  --wandering-river-oklch: oklch(0.684 0.068 238);
}

.element {
  color: var(--wandering-river);
  background-color: hsl(204 38% 60%);
  border-color: oklch(0.684 0.068 238);
}

Tailwind CSS v4

@theme {
  --color-wandering-river: #71a0bf;
  --color-wandering-river-50: #e4f8ff;
  --color-wandering-river-100: #d4ecfd;
  --color-wandering-river-200: #bbd9ef;
  --color-wandering-river-300: #98bdd7;
  --color-wandering-river-400: #78a5c2;
  --color-wandering-river-500: #598dae;
  --color-wandering-river-600: #4c7793;
  --color-wandering-river-700: #3d5f76;
  --color-wandering-river-800: #2a4657;
  --color-wandering-river-900: #1c313d;
  --color-wandering-river-950: #0c1d26;
}

SCSS

$wandering-river: #71a0bf;
$wandering-river-rgb: 113, 160, 191;
$wandering-river-light: mix(#fff, $wandering-river, 20%);
$wandering-river-dark: mix(#000, $wandering-river, 20%);

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