If there is a very special css code, will the pagespeed value decrease?
@fffddd-dfeeedd in most cases, no - although an example of what you are looking to do would be beneficial
@phenomlabd 1- I changed the theme color codes
2- I added a dark theme and changed the color codes.
@fffddd-dfeeedd That won't have much (if any) impact on site speed as the CSS is minified before delivery
@phenomlab Is there a nodebb custom plugin?
@fffddd-dfeeedd Yes, nodebb-plugin-customize which will allow you to change templates etc.