Tools: Lenovo laptop e460, Windows 10 system, Photoshop20 17.

1, ps, according to the actual situation of the picture to be processed, select the appropriate selection tool. If you need to paint some shapes, you can use the rectangle box selection tool and the ellipse box selection tool; If you need to select an existing area on the screen, you can choose lasso tool, magic wand tool, pen tool, etc.

2. Select the designated area to be colored on the canvas.

3. In the foreground color, set the desired color.

4. You can directly press the shortcut key "alt+delete" to fill the foreground color.

5. You can also select the paint bucket tool after selecting the selection in the box. Then use the paint bucket tool to click on the selected position to draw.

6. You can also use the brush tool after selecting the selection, and then use the brush tool to draw and color in the specified selection. Because the box selects the selection, all the colors of the brush will not exceed the range of the selection.