#679DE1

CSS

:root {
  --blue-bay: #679de1;
  --blue-bay-rgb: 103 157 225;
  --blue-bay-oklch: oklch(0.687 0.116 254.8);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(213 67% 64%);
  border-color: oklch(0.687 0.116 254.8);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #679de1;
  --color-blue-bay-50: #e0f7ff;
  --color-blue-bay-100: #d0eaff;
  --color-blue-bay-200: #b5d7ff;
  --color-blue-bay-300: #91baf3;
  --color-blue-bay-400: #6ea1e2;
  --color-blue-bay-500: #4d88d1;
  --color-blue-bay-600: #4273b1;
  --color-blue-bay-700: #345c8e;
  --color-blue-bay-800: #224469;
  --color-blue-bay-900: #172f4a;
  --color-blue-bay-950: #081b31;
}

SCSS

$blue-bay: #679de1;
$blue-bay-rgb: 103, 157, 225;
$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);
}