Module:Color/styles.css

/* Template:Color will not work in night theme. If the colors are semantically important for your article, and it is important these colors appear in night mode, it is suggested you create a template specifically targeted at your use case rather than using the generic color template. */

html.skin-theme-clientpref-night .tmp-color {
   color: inherit !important;
}
@media (prefers-color-scheme: dark) {
    /* automatic mode */
    html.skin-theme-clientpref-os .tmp-color {
      color: inherit !important;
    }
}