#3B7B9D

CSS

:root {
  --cry-me-a-river: #3b7b9d;
  --cry-me-a-river-rgb: 59 123 157;
  --cry-me-a-river-oklch: oklch(0.555 0.084 234.3);
}

.element {
  color: var(--cry-me-a-river);
  background-color: hsl(201 45% 42%);
  border-color: oklch(0.555 0.084 234.3);
}

Tailwind CSS v4

@theme {
  --color-cry-me-a-river: #3b7b9d;
  --color-cry-me-a-river-50: #dffaff;
  --color-cry-me-a-river-100: #ceedff;
  --color-cry-me-a-river-200: #b3dbf4;
  --color-cry-me-a-river-300: #8ebfdd;
  --color-cry-me-a-river-400: #6ba7c9;
  --color-cry-me-a-river-500: #478fb6;
  --color-cry-me-a-river-600: #3d7999;
  --color-cry-me-a-river-700: #31617b;
  --color-cry-me-a-river-800: #21475b;
  --color-cry-me-a-river-900: #16313f;
  --color-cry-me-a-river-950: #071d28;
}

SCSS

$cry-me-a-river: #3b7b9d;
$cry-me-a-river-rgb: 59, 123, 157;
$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);
}