There is no touch-up paint for the black handrail, as it is an anodized finish and cannot be matched with paint. One of the advantages of anodizing, though, is that small scuff marks and even light scratches can be removed with a mildly abrasive cleanser like Comet or Barkeepers Friend.
For the Satin Black hardware, we have found that Behr Premium Satin Black aerosol paint is a near-perfect match. You can repaint an entire bracket or bend and the look will be virtually indistinguishable, or you can spray it into a cup and apply it with a brush to small knicks if you prefer.
The fastest way to get this to you is for you to purchase it online or pick it up at a local Home Depot store:
