I use image editor with filter function and set the red to 50 and it works, but when I try setting back red to 1 it didn’t work. But I can still increase more than. 50. What I meant is that I can’t set the image back to normal.
Because you put filter to an image which is already filtered (when you apply red50 to it).
Try to save the original image too and when user put filter to original image, it will work.