I followed the guidance to update the theme colors using the variables file.

$primary: if(isDarkMode(), #1C108F, #32279A) !default;

However, I have elected to use the dark theme and deployed it successfully, yet the theme color changes, show up when I run re-run GULP on the light version, but not the dark. Am I missing a step or something to alter the theme color of the dark theme? Any help would be appreciated.