Reservoir

CSS

:root {
  --reservoir: #01638b;
  --reservoir-rgb: 1 99 139;
  --reservoir-oklch: oklch(0.472 0.1 235.1);
}

.element {
  color: var(--reservoir);
  background-color: hsl(197 99% 27%);
  border-color: oklch(0.472 0.1 235.1);
}

Tailwind CSS v4

@theme {
  --color-reservoir: #01638b;
  --color-reservoir-50: #dbfaff;
  --color-reservoir-100: #caeeff;
  --color-reservoir-200: #acdbfa;
  --color-reservoir-300: #86c0e4;
  --color-reservoir-400: #5fa8d1;
  --color-reservoir-500: #3590bf;
  --color-reservoir-600: #2f7aa1;
  --color-reservoir-700: #256281;
  --color-reservoir-800: #17485f;
  --color-reservoir-900: #0f3243;
  --color-reservoir-950: #021e2b;
}

SCSS

$reservoir: #01638b;
$reservoir-rgb: 1, 99, 139;
$reservoir-light: mix(#fff, $reservoir, 20%);
$reservoir-dark: mix(#000, $reservoir, 20%);

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