#5973B0

CSS

:root {
  --loch-ness: #5973b0;
  --loch-ness-rgb: 89 115 176;
  --loch-ness-oklch: oklch(0.562 0.1 265.8);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(222 36% 52%);
  border-color: oklch(0.562 0.1 265.8);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #5973b0;
  --color-loch-ness-50: #e9f5ff;
  --color-loch-ness-100: #d9e8ff;
  --color-loch-ness-200: #c2d4ff;
  --color-loch-ness-300: #a1b6eb;
  --color-loch-ness-400: #829dda;
  --color-loch-ness-500: #6784c9;
  --color-loch-ness-600: #5770a9;
  --color-loch-ness-700: #455988;
  --color-loch-ness-800: #304265;
  --color-loch-ness-900: #212d47;
  --color-loch-ness-950: #101a2e;
}

SCSS

$loch-ness: #5973b0;
$loch-ness-rgb: 89, 115, 176;
$loch-ness-light: mix(#fff, $loch-ness, 20%);
$loch-ness-dark: mix(#000, $loch-ness, 20%);

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