#397B9E

CSS

:root {
  --cry-me-a-river: #397b9e;
  --cry-me-a-river-rgb: 57 123 158;
  --cry-me-a-river-oklch: oklch(0.555 0.086 234.5);
}

.element {
  color: var(--cry-me-a-river);
  background-color: hsl(201 47% 42%);
  border-color: oklch(0.555 0.086 234.5);
}

Tailwind CSS v4

@theme {
  --color-cry-me-a-river: #397b9e;
  --color-cry-me-a-river-50: #dffaff;
  --color-cry-me-a-river-100: #ceedff;
  --color-cry-me-a-river-200: #b2dbf5;
  --color-cry-me-a-river-300: #8dbfde;
  --color-cry-me-a-river-400: #69a7ca;
  --color-cry-me-a-river-500: #458fb7;
  --color-cry-me-a-river-600: #3c799a;
  --color-cry-me-a-river-700: #2f617c;
  --color-cry-me-a-river-800: #20475b;
  --color-cry-me-a-river-900: #153140;
  --color-cry-me-a-river-950: #061d29;
}

SCSS

$cry-me-a-river: #397b9e;
$cry-me-a-river-rgb: 57, 123, 158;
$cry-me-a-river-light: mix(#fff, $cry-me-a-river, 20%);
$cry-me-a-river-dark: mix(#000, $cry-me-a-river, 20%);

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