#686BC6

CSS

:root {
  --loch-ness: #686bc6;
  --loch-ness-rgb: 104 107 198;
  --loch-ness-oklch: oklch(0.569 0.138 279.6);
}

.element {
  color: var(--loch-ness);
  background-color: hsl(238 45% 59%);
  border-color: oklch(0.569 0.138 279.6);
}

Tailwind CSS v4

@theme {
  --color-loch-ness: #686bc6;
  --color-loch-ness-50: #eef1ff;
  --color-loch-ness-100: #dfe3ff;
  --color-loch-ness-200: #caceff;
  --color-loch-ness-300: #abaffd;
  --color-loch-ness-400: #8e94ee;
  --color-loch-ness-500: #7579df;
  --color-loch-ness-600: #6366bc;
  --color-loch-ness-700: #4f5297;
  --color-loch-ness-800: #383c71;
  --color-loch-ness-900: #262950;
  --color-loch-ness-950: #151735;
}

SCSS

$loch-ness: #686bc6;
$loch-ness-rgb: 104, 107, 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);
}