[MRM]

My practice includes quite a bit of construction litigation, most of it related to stucco installed since the building codes changed in the 1990s. I would strongly discourage any coating on the stucco surface. I don't think you should cover a porous material like stucco with an elastomeric finish that doesn't breathe. My recommendation is to simply have the contractor run a big batch of the finish coat he's applying to the new areas and just skim coat the old stucco areas with the new color coat. Everything matches and everything stays natural.