#586FC6

CSS

:root {
  --loch-ness: #586fc6;
  --loch-ness-rgb: 88 111 198;
  --loch-ness-oklch: oklch(0.566 0.137 270.4);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(227 49% 56%);
  border-color: oklch(0.566 0.137 270.4);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #586fc6;
  --color-loch-ness-50: #e7f4ff;
  --color-loch-ness-100: #d8e6ff;
  --color-loch-ness-200: #c0d1ff;
  --color-loch-ness-300: #9fb3fe;
  --color-loch-ness-400: #8099ef;
  --color-loch-ness-500: #647ee0;
  --color-loch-ness-600: #556bbd;
  --color-loch-ness-700: #445698;
  --color-loch-ness-800: #2e3f71;
  --color-loch-ness-900: #1f2b50;
  --color-loch-ness-950: #0f1835;
}

SCSS

$loch-ness: #586fc6;
$loch-ness-rgb: 88, 111, 198;
$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);
}