My favorite color was Harvest Gold, but unfortunately it was discontinued! I think that for the money they would charge to paint your'e appliance it would be cheaper to replace and that includes efficiency.
Plum, don't forget the Avacado Green or that lovely brown. LOL I agree that 30+ yrs. is about the end of the service life in this era of appliances.
If you are adamant in keeping them, check out an appliance recycler for advice. Maybe they'll also have some newer, used appliances in modern colors.