styles in a sharepoint list

Power AppsPower Apps Style Guide: 3 Great Ways To Consistently Brand Your Apps

By saving in a data source like SharePoint and then connect it with Power Apps, you can easily have a centralized style library. This ensures that all your apps look consistent and you don't have to go through the hassle and change every element, once you decided to change your primaryAccent color. It makes sense to take your time to sit down, think of the way you'd like your styles to be structured and stay with that through all your app-creations.