#6D9ED3

CSS

:root {
  --blue-bay: #6d9ed3;
  --blue-bay-rgb: 109 158 211;
  --blue-bay-oklch: oklch(0.686 0.095 251.2);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(211 54% 63%);
  border-color: oklch(0.686 0.095 251.2);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #6d9ed3;
  --color-blue-bay-50: #e3f7ff;
  --color-blue-bay-100: #d2eaff;
  --color-blue-bay-200: #b8d7fd;
  --color-blue-bay-300: #95bbe7;
  --color-blue-bay-400: #74a2d5;
  --color-blue-bay-500: #548ac3;
  --color-blue-bay-600: #4875a5;
  --color-blue-bay-700: #395d84;
  --color-blue-bay-800: #274562;
  --color-blue-bay-900: #1a3045;
  --color-blue-bay-950: #0a1c2c;
}

SCSS

$blue-bay: #6d9ed3;
$blue-bay-rgb: 109, 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);
}