A SharePoint Online theme is a collection of settings that determine the look and feel of a SharePoint site. The theme includes settings for colors, fonts, and other visual elements. It allows you to customize the appearance of your SharePoint site to match your organization's brand or style.
You can use the default themes provided by SharePoint, or you can create your own custom theme by selecting specific colors and fonts. Once you have chosen a theme, you can apply it to your entire site or to specific pages or subsites.
In this post I’ll show you how to create your own custom theme for SharePointOnline for your site designers to take advantage of in your tenant!
To design your theme, you can go to the Microsoft Fluent UI Theme Designer. Once you’ve set your colours and they’re looking how you want, ensure that the accessibility checker is passing and then export your theme. You’ll want to copy the export on the PowerShell tab for this guide.