#407B9B

CSS

:root {
  --cry-me-a-river: #407b9b;
  --cry-me-a-river-rgb: 64 123 155;
  --cry-me-a-river-oklch: oklch(0.557 0.079 234.4);
}

.element {
  color: var(--cry-me-a-river);
  background-color: hsl(201 42% 43%);
  border-color: oklch(0.557 0.079 234.4);
}

Tailwind CSS v4

@theme {
  --color-cry-me-a-river: #407b9b;
  --color-cry-me-a-river-50: #e1f9ff;
  --color-cry-me-a-river-100: #d0edff;
  --color-cry-me-a-river-200: #b5daf2;
  --color-cry-me-a-river-300: #91bedb;
  --color-cry-me-a-river-400: #6fa7c6;
  --color-cry-me-a-river-500: #4c8fb3;
  --color-cry-me-a-river-600: #417997;
  --color-cry-me-a-river-700: #346179;
  --color-cry-me-a-river-800: #234759;
  --color-cry-me-a-river-900: #18313e;
  --color-cry-me-a-river-950: #081d28;
}

SCSS

$cry-me-a-river: #407b9b;
$cry-me-a-river-rgb: 64, 123, 155;
$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);
}