#3A7BA2

CSS

:root {
  --cry-me-a-river: #3a7ba2;
  --cry-me-a-river-rgb: 58 123 162;
  --cry-me-a-river-oklch: oklch(0.557 0.09 237.7);
}

.element {
  color: var(--cry-me-a-river);
  background-color: hsl(203 47% 43%);
  border-color: oklch(0.557 0.09 237.7);
}

Tailwind CSS v4

@theme {
  --color-cry-me-a-river: #3a7ba2;
  --color-cry-me-a-river-50: #dff9ff;
  --color-cry-me-a-river-100: #ceedff;
  --color-cry-me-a-river-200: #b2daf7;
  --color-cry-me-a-river-300: #8dbee1;
  --color-cry-me-a-river-400: #69a6cd;
  --color-cry-me-a-river-500: #458eba;
  --color-cry-me-a-river-600: #3c799d;
  --color-cry-me-a-river-700: #30607e;
  --color-cry-me-a-river-800: #20475d;
  --color-cry-me-a-river-900: #153141;
  --color-cry-me-a-river-950: #061d2a;
}

SCSS

$cry-me-a-river: #3a7ba2;
$cry-me-a-river-rgb: 58, 123, 162;
$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);
}