#709ED3

CSS

:root {
  --blue-bay: #709ed3;
  --blue-bay-rgb: 112 158 211;
  --blue-bay-oklch: oklch(0.687 0.093 252.6);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(212 53% 63%);
  border-color: oklch(0.687 0.093 252.6);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #709ed3;
  --color-blue-bay-50: #e4f7ff;
  --color-blue-bay-100: #d3eaff;
  --color-blue-bay-200: #bad7fc;
  --color-blue-bay-300: #97bae7;
  --color-blue-bay-400: #76a2d4;
  --color-blue-bay-500: #5789c2;
  --color-blue-bay-600: #4a74a4;
  --color-blue-bay-700: #3b5d84;
  --color-blue-bay-800: #284462;
  --color-blue-bay-900: #1b2f44;
  --color-blue-bay-950: #0b1c2c;
}

SCSS

$blue-bay: #709ed3;
$blue-bay-rgb: 112, 158, 211;
$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);
}