#6358E1

CSS

:root {
  --warm-blue: #6358e1;
  --warm-blue-rgb: 99 88 225;
  --warm-blue-oklch: oklch(0.549 0.201 281.1);
}

.element {
  color: var(--warm-blue);
  background-color: hsl(245 70% 61%);
  border-color: oklch(0.549 0.201 281.1);
}

Tailwind CSS v4

@theme {
  --color-warm-blue: #6358e1;
  --color-warm-blue-50: #ecefff;
  --color-warm-blue-100: #dee0ff;
  --color-warm-blue-200: #c8c9ff;
  --color-warm-blue-300: #aaa8ff;
  --color-warm-blue-400: #8d8aff;
  --color-warm-blue-500: #756aff;
  --color-warm-blue-600: #635bdc;
  --color-warm-blue-700: #4f48b1;
  --color-warm-blue-800: #373585;
  --color-warm-blue-900: #25245e;
  --color-warm-blue-950: #141241;
}

SCSS

$warm-blue: #6358e1;
$warm-blue-rgb: 99, 88, 225;
$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);
}