#5F59E0

CSS

:root {
  --warm-blue: #5f59e0;
  --warm-blue-rgb: 95 89 224;
  --warm-blue-oklch: oklch(0.547 0.199 279.5);
}

.element {
  color: var(--warm-blue);
  background-color: hsl(243 69% 61%);
  border-color: oklch(0.547 0.199 279.5);
}

Tailwind CSS v4

@theme {
  --color-warm-blue: #5f59e0;
  --color-warm-blue-50: #ebefff;
  --color-warm-blue-100: #dce1ff;
  --color-warm-blue-200: #c6caff;
  --color-warm-blue-300: #a7a9ff;
  --color-warm-blue-400: #898cff;
  --color-warm-blue-500: #726cff;
  --color-warm-blue-600: #605cdb;
  --color-warm-blue-700: #4c4ab1;
  --color-warm-blue-800: #353685;
  --color-warm-blue-900: #24255e;
  --color-warm-blue-950: #131340;
}

SCSS

$warm-blue: #5f59e0;
$warm-blue-rgb: 95, 89, 224;
$warm-blue-light: mix(#fff, $warm-blue, 20%);
$warm-blue-dark: mix(#000, $warm-blue, 20%);

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