Here is a good article about bumblefoot, and at the end, there is a picture and a video of applying the dressing:
https://the-chicken-chick.com/bumblefoot-causes-treatment-warning/
Yellow color can also be fat, and not always pus. One good way of treating bumblefoot, especially since you have already done the surgery, is to use a sugardine paste plaster on the foot and keep it bandaged. That is to take Betadine/povidone iodine and mix it with sugar in a container. Every...