Can you Paint rock dash stucco?

YES, but first remove any loose or flaking paint then make sure the surface is clean and free of dirt, then you must apply a bonding agent (glue) a.k.a. concrete bonding adhesive, this can be done just like painting with a paint roller. MAKE SURE YOU COVER ENTIRE AREA WITH ADHESIVE BECAUSE IF YOU MISS A SPOT YOUR FRESH COAT OF STUCCO WILL LIKELY CHIP OR FLAKE OFF!