Power BI has three themes to choose from: Light, Dark or Color-blind friendly. A dashboard’s theme can even be personalized by selecting the Custom theme option.

Advance your skills in Power BI dashboard by reading more of our detailed content. How to Use SVG and DAX for Custom Power BI Visuals Using Excel Power BI Desktop to build Interactive Dashboards ...

Learn how to create stunning Power BI dashboards with this beginner’s guide. Tips, tricks, and techniques for impactful visualizations.

Such customizations involve using a ".PBIT file," which is Microsoft's name for Power BI Desktop templates that are available from the Microsoft Download Center, according to the FAQ document.