#5F9EE5

CSS

:root {
  --blue-bay: #5f9ee5;
  --blue-bay-rgb: 95 158 229;
  --blue-bay-oklch: oklch(0.687 0.124 252.6);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(212 72% 64%);
  border-color: oklch(0.687 0.124 252.6);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #5f9ee5;
  --color-blue-bay-50: #def8ff;
  --color-blue-bay-100: #ccebff;
  --color-blue-bay-200: #b1d8ff;
  --color-blue-bay-300: #8bbbf6;
  --color-blue-bay-400: #66a2e6;
  --color-blue-bay-500: #4289d5;
  --color-blue-bay-600: #3974b4;
  --color-blue-bay-700: #2e5d91;
  --color-blue-bay-800: #1d446b;
  --color-blue-bay-900: #132f4c;
  --color-blue-bay-950: #051b32;
}

SCSS

$blue-bay: #5f9ee5;
$blue-bay-rgb: 95, 158, 229;
$blue-bay-light: mix(#fff, $blue-bay, 20%);
$blue-bay-dark: mix(#000, $blue-bay, 20%);

.element {
  color: $blue-bay;
  box-shadow: 0 0 0 2px rgba($blue-bay, 0.35);
}