Guide

1. Inside the main dashboard of your SharePoint site, navigate to the top-right corner and click the 'Settings' icon.

2. Choose 'Site Branding' from the list of options.

3. After that, tap the 'New Theme' button under Themes.

4. Subsequently, tap the 'Primary Color' menu to get started.

5. Use the color picker panel to specify your preferred color and then tap 'Save' to apply your input.

6. Repeat the same series of steps for Text Color, Background Color, and Accent Color. Once done, tap 'Next' to proceed further.

7. Come up with a unique theme name and then enter it into the provided input field.

8. Following that, click 'Save'.

9. After completing these steps, the new SharePoint site theme will be created and saved.