Gross Tattoo

My husband is getting a tattoo to cover an old tattoo. He got the outline done and some of the coloring done when they had to stop because he was bleeding too much and the color wasn't taking. It has been healing pretty good except for the colored in places. One is really bad and it looks like all the color is gone and there is a meaty hole in his arm the shape of the part of the tattoo. What do I need to do to fix this and prevent it from happening again. Thanks