Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
I work as an administrator and have been asked to change the look of a few sites. We have sharepoint 2013 on-premise. Are there any risks of override the existing CSS? Is there something I should definitely avoid?
On-prem, that will be risk free as the DOM won't change for that product. It becomes a larger issue in SharePoint Online where the DOM can change at any time as Microsoft updates the product.
SharePoint Color Palette Tool is I guess one of the best and simpler tools for branding / changing CSS for the site.
You can refer this for How-to do stuff
Alternatively, you can also try Alternative CSS URL
All the best!
Required, but never shown