#357BA3

CSS

:root {
  --cry-me-a-river: #357ba3;
  --cry-me-a-river-rgb: 53 123 163;
  --cry-me-a-river-oklch: oklch(0.556 0.093 236.9);
}

.element {
  color: var(--cry-me-a-river);
  background-color: hsl(202 51% 42%);
  border-color: oklch(0.556 0.093 236.9);
}

Tailwind CSS v4

@theme {
  --color-cry-me-a-river: #357ba3;
  --color-cry-me-a-river-50: #defaff;
  --color-cry-me-a-river-100: #ccedff;
  --color-cry-me-a-river-200: #b0dbf8;
  --color-cry-me-a-river-300: #8bbfe2;
  --color-cry-me-a-river-400: #66a7cf;
  --color-cry-me-a-river-500: #408fbc;
  --color-cry-me-a-river-600: #38799f;
  --color-cry-me-a-river-700: #2c617f;
  --color-cry-me-a-river-800: #1d475e;
  --color-cry-me-a-river-900: #133142;
  --color-cry-me-a-river-950: #051d2a;
}

SCSS

$cry-me-a-river: #357ba3;
$cry-me-a-river-rgb: 53, 123, 163;
$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);
}