Lighting may or may not be part of the DJ set up. If you want to keep things very subdued, be sure to explain what you consider tasteful and what is really over the top. Strobe lights, colored lights and even disco balls may be ideal in some receptions, but may not be considered appropriate at others.
If you have a wedding receptions with lots of activities, you should provide the DJ with a written itinerary. This will allow the DJ to understand what is happening at what times and plan the music accordingly. The DJ should be willing to work around the other events you have planned, and may even be able to provide lighting, cordless mikes and special sound effects to enhance the other events at the reception.