How to fill the gradient background
You will be the amazing reporter with WPS Presentation, which could be an alternative to Microsoft PowerPoint.
1. Open the presentation file in WPS Office.
2. click the design tab, then select background, and pick the color you like.
3. Select gradient fill at the filling point, and select the gradient fill style.
4. Click Objecting formatting on the sidebar, where you could change the fill style, gradient style, angle, color, position, transparency and brightness of the background.
5. When you finish all the set, click apply to all to apply this formatting to the rest of your slide.