Greyish Blue

CSS

:root {
  --greyish-blue: #5e819d;
  --greyish-blue-rgb: 94 129 157;
  --greyish-blue-oklch: oklch(0.588 0.059 243.1);
}

.element {
  color: var(--greyish-blue);
  background-color: hsl(207 25% 49%);
  border-color: oklch(0.588 0.059 243.1);
}

Tailwind CSS v4

@theme {
  --color-greyish-blue: #5e819d;
  --color-greyish-blue-50: #e8f7ff;
  --color-greyish-blue-100: #d8eafb;
  --color-greyish-blue-200: #c0d8ec;
  --color-greyish-blue-300: #9fbbd4;
  --color-greyish-blue-400: #81a3bf;
  --color-greyish-blue-500: #648baa;
  --color-greyish-blue-600: #557690;
  --color-greyish-blue-700: #445e73;
  --color-greyish-blue-800: #304555;
  --color-greyish-blue-900: #20303b;
  --color-greyish-blue-950: #101c25;
}

SCSS

$greyish-blue: #5e819d;
$greyish-blue-rgb: 94, 129, 157;
$greyish-blue-light: mix(#fff, $greyish-blue, 20%);
$greyish-blue-dark: mix(#000, $greyish-blue, 20%);

.element {
  color: $greyish-blue;
  box-shadow: 0 0 0 2px rgba($greyish-blue, 0.35);
}