#6C9FD3

CSS

:root {
  --blue-bay: #6c9fd3;
  --blue-bay-rgb: 108 159 211;
  --blue-bay-oklch: oklch(0.687 0.095 249.8);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(210 54% 63%);
  border-color: oklch(0.687 0.095 249.8);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #6c9fd3;
  --color-blue-bay-50: #e2f8ff;
  --color-blue-bay-100: #d2ebff;
  --color-blue-bay-200: #b8d8fc;
  --color-blue-bay-300: #94bbe7;
  --color-blue-bay-400: #72a3d4;
  --color-blue-bay-500: #528ac2;
  --color-blue-bay-600: #4675a4;
  --color-blue-bay-700: #385e84;
  --color-blue-bay-800: #264561;
  --color-blue-bay-900: #193044;
  --color-blue-bay-950: #0a1c2c;
}

SCSS

$blue-bay: #6c9fd3;
$blue-bay-rgb: 108, 159, 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);
}