#679DE5

CSS

:root {
  --blue-bay: #679de5;
  --blue-bay-rgb: 103 157 229;
  --blue-bay-oklch: oklch(0.689 0.121 256);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(214 71% 65%);
  border-color: oklch(0.689 0.121 256);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #679de5;
  --color-blue-bay-50: #e0f7ff;
  --color-blue-bay-100: #cfeaff;
  --color-blue-bay-200: #b4d6ff;
  --color-blue-bay-300: #91b9f5;
  --color-blue-bay-400: #6da1e5;
  --color-blue-bay-500: #4c87d5;
  --color-blue-bay-600: #4173b4;
  --color-blue-bay-700: #345c90;
  --color-blue-bay-800: #22436b;
  --color-blue-bay-900: #172f4b;
  --color-blue-bay-950: #081b32;
}

SCSS

$blue-bay: #679de5;
$blue-bay-rgb: 103, 157, 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);
}