What should I do if I forget to bring colored paper and towels for the color joint exam?

Borrow from others. If you forget to bring colored paper and towels when taking the color joint exam, you can ask other candidates if they have any extra colored paper and towels. You can borrow them from others and repay or pay them after the exam. There is no other way, because once you enter the examination room, you are not allowed to leave the examination room, nor can you use electronic equipment, so you can only borrow it from others.