First of all, you can't just put maintenance oil on leather clothes. If the maintenance oil is used for a long time, it will lead to leather surface aging, leather hardening and loss of elasticity. When we are nursing, we will first clean, iron and shape, and then use natural fatliquoring agent to fatliquor, so as to ensure that the leather clothes absorb nutrients. Finally, it will be sprayed with professional dyes, and finally it will be waterproof and oil-proof. There are more than a dozen processes before and after the actual operation.
In your case, if I judge, it should be smooth leather, so it is not difficult to deal with it. Clean the nursing oil on the surface first. Of course, if it penetrates into the leather board, it can't be cleaned. Then follow the steps described above for care, and it is very easy to color and cover the colored part.
There is almost no way to deal with it at home, and professional treatment can achieve the decoration effect.