#387B9F

CSS

:root {
  --cry-me-a-river: #387b9f;
  --cry-me-a-river-rgb: 56 123 159;
  --cry-me-a-river-oklch: oklch(0.555 0.088 234.9);
}

.element {
  color: var(--cry-me-a-river);
  background-color: hsl(201 48% 42%);
  border-color: oklch(0.555 0.088 234.9);
}

Tailwind CSS v4

@theme {
  --color-cry-me-a-river: #387b9f;
  --color-cry-me-a-river-50: #dffaff;
  --color-cry-me-a-river-100: #cdedff;
  --color-cry-me-a-river-200: #b2dbf6;
  --color-cry-me-a-river-300: #8cbfdf;
  --color-cry-me-a-river-400: #69a7cb;
  --color-cry-me-a-river-500: #448fb8;
  --color-cry-me-a-river-600: #3b799b;
  --color-cry-me-a-river-700: #2f617d;
  --color-cry-me-a-river-800: #1f475c;
  --color-cry-me-a-river-900: #143140;
  --color-cry-me-a-river-950: #061d29;
}

SCSS

$cry-me-a-river: #387b9f;
$cry-me-a-river-rgb: 56, 123, 159;
$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);
}