How to change the background of a photo to blue?

Then click the matting pen.

1, and then there are three modes of matting, and automatic matting is usually selected, which is convenient and quick. As shown in the figure:

2. Next, draw a few strokes on the characters with a shading pen. Then click finish matting.

3. At this point, the drawn figure has no background color. At this time, you can add the background color needed for the photo.

4. Click on the background setting in the upper right corner, and then select the color. At this time, you can choose the color you need for the photo. Like blue. As shown in the figure:

5. As shown in the figure, after selecting blue, you can get a blue background photo. Then click OK or Save.