#6355D8

CSS

:root {
  --warm-blue: #6355d8;
  --warm-blue-rgb: 99 85 216;
  --warm-blue-oklch: oklch(0.538 0.193 282.6);
}

.element {
  color: var(--warm-blue);
  background-color: hsl(246 63% 59%);
  border-color: oklch(0.538 0.193 282.6);
}

Tailwind CSS v4

@theme {
  --color-warm-blue: #6355d8;
  --color-warm-blue-50: #eeeeff;
  --color-warm-blue-100: #e0e0ff;
  --color-warm-blue-200: #cbc9ff;
  --color-warm-blue-300: #ada8ff;
  --color-warm-blue-400: #908bff;
  --color-warm-blue-500: #796bff;
  --color-warm-blue-600: #665bd7;
  --color-warm-blue-700: #5249ad;
  --color-warm-blue-800: #393582;
  --color-warm-blue-900: #27255c;
  --color-warm-blue-950: #16123f;
}

SCSS

$warm-blue: #6355d8;
$warm-blue-rgb: 99, 85, 216;
$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);
}