How to set the red value as needed:
1. First, you can find a reference picture and open it in the PS program, as shown below.
2. Then click the straw working tool in the toolbar on the left, as shown below.
3. Click on the red position of the open seal with the straw tool, and you can find that the foreground color selector has turned red, as shown below.
4. Click the foreground color selector, and you can see the red value of the selected seal in the opened window, as shown in the figure below.