acrylic black, you can easily wipe it off (before it thoroughly dries) with a solution of rubbing alcohol and water. Use a mostly de-fuzzed q-tip. That will not harm the silver real lacquer or fully-cured enamel. You can always go back and touch-up small spots of either color until it is right. (Do not use Tamiya or Testors "lacquers" for the silver. Alcohol dissolves them.)