Wait a minute! Those blotches are telling you the repair job was flawed from the get-go. Maybe the surface wasn't clean or the primer was off. Spot fixing a silver blend is basically hopeless, you'll always see it in certain light. Why pour more money into a quick fix that'll just look worse later? A full repaint is the only way to make it right, so why fight it?
Look at the repair under different lights first. A really good painter can sometimes blend silver if everything is just right. @patb65 isn't wrong though, a full repaint usually saves headache later.
Silver is just about the hardest color to get right for a spot repair. My own car had a similar botch job last year, and no matter how much they tried to buff it, you could see the ghost of the repair in the afternoon sun. Those blotches mean the layers underneath are wrong, and anything you put on top will just sit differently. It's a tough lesson, but paying once for a full panel repaint beats wasting cash on three partial fixes that never look right.