#619EE3

CSS

:root {
  --blue-bay: #619ee3;
  --blue-bay-rgb: 97 158 227;
  --blue-bay-oklch: oklch(0.687 0.121 252.6);
}

.element {
  color: var(--blue-bay);
  background-color: hsl(212 70% 64%);
  border-color: oklch(0.687 0.121 252.6);
}

Tailwind CSS v4

@theme {
  --color-blue-bay: #619ee3;
  --color-blue-bay-50: #def8ff;
  --color-blue-bay-100: #cdebff;
  --color-blue-bay-200: #b2d7ff;
  --color-blue-bay-300: #8dbbf4;
  --color-blue-bay-400: #68a2e4;
  --color-blue-bay-500: #4589d3;
  --color-blue-bay-600: #3b74b2;
  --color-blue-bay-700: #2f5d8f;
  --color-blue-bay-800: #1e446a;
  --color-blue-bay-900: #142f4b;
  --color-blue-bay-950: #061b31;
}

SCSS

$blue-bay: #619ee3;
$blue-bay-rgb: 97, 158, 227;
$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);
}