MediaWiki:Citizen.css

/* All CSS here will be loaded for users of the Citizen skin */
:root.skin-citizen-dark {
    --color-primary__l: 60%;
    --color-primary__h: 204;
    --color-primary__s: 54%;
    --color-surface-0: hsl(var(--color-primary__h),35%,12%);
    --color-surface-1: hsl(var(--color-primary__h),35%,12%);
}