@salesforce-ux/design-system/design-tokens/dist/transparent-colors.json

Salesforce Lightning Design System

{
  "color-neutral-10-opacity-10": "rgba(24, 24, 24, 0.1)",
  "color-neutral-10-opacity-25": "rgba(24, 24, 24, 0.25)",
  "color-neutral-10-opacity-50": "rgba(24, 24, 24, 0.5)",
  "color-neutral-10-opacity-75": "rgba(24, 24, 24, 0.75)",
  "color-neutral-100-opacity-10": "rgba(255, 255, 255, 0.1)",
  "color-neutral-100-opacity-25": "rgba(255, 255, 255, 0.25)",
  "color-neutral-100-opacity-50": "rgba(255, 255, 255, 0.5)",
  "color-neutral-100-opacity-75": "rgba(255, 255, 255, 0.75)"
}