Originally posted by: y2kc
primer first then the paint, a couple of coats (of the paint) should do it.
edit: the primer basically "covers" the dark color and serves as a base for the new color. primer is much cheaper than the colored paint.
Your primers are typically quite thin, with little pigment, and don't usually cover very well. They are used mostly to bond different types of paint together, or to apply to bae wood, drywall, etc.
Your best bet is to buy a high quality paint, apply the first coat, then let dry completely, then apply a second coat. There is a trick called "backrolling", you roll the paint on the wall, and keep an eye on it. As soon as it starts to dry slightly, just roll back over it with a "dry" roller (One you are using, just don't keep dipping it back into the paint.)
The key word here is "QUALITY", the cheap stuff will not cover as well as the Brand names, and would likely require several coats to cover. (Ask my wife about "Wal-Mart" paint, after she put six coats on my daughters kitchen!
Oh Yeah, invest in a 5 Gallon bucket, a "Roller screen", and an extension pole. The pros always use these, it is much better than the roller trays.