Is it reasonable to charge a new fee for painting the wall of the property?

This practice of property is unfounded, whether it is property management regulations or some property-related regulations customized by local governments. This is just a unilateral customization of the property, and you can not obey it. Of course, you can also ask them to take out the approval documents of the relevant price departments to check, because all the relevant fees for property services must be reported to the price department for approval, and the fees can only be formally charged after approval. If there is no approval document, it is illegal and you can refuse to pay.