You will need to mud and sand down the patch and repaint the area or even the entire ceiling if the color differences are significant (or get someone to do it). a Handyman may charge you about $100 to do it. 

Hi BP,I recently purchased my first investment property and quote excited!  The renovation is going well as far as I can tell.  My present dilemma is the bathtub.  It is has yellow stains  which I thought would be an ...

So we chose that route and repainted, added baseboards, refinished the bathroom cabinets, added granite to the kitchen and bathrooms, added used stainless appliances, and cleaned up the yard and house.

To all fellow landlords, just wondering if you ever had a prospective tenant who asked if the master's bedroom could be painted to a different color or have the doors re-painted.

Hmm, maybe we should repaint the front door to a different color.

No repaint...no clean up...no nothing.  

We didn't repaint the whole house.  

I would only charge a tenant if there was actual damages beyond normal wear and tear like crayon/drawings on the walls, holes, big scruffs, etc.Touching up the paint between tenants is normal but if the entire home needed to be re-painted including the ceilings as the OP had said I would consider that more than normal wear and tear, that is if the home had fresh or close to fresh paint when they moved in.

For example, the most common cosmetic, or non essential, request we receive is to repaint a room - usually a bedroom - to a colour selected by the tenant.  

Also, I do realize that if I hammer a couple back into place there is the likelihood that they may bump again in years to come.Lastly, I'm venturing on this small project because I am preparing to completely repaint every room in the house.