Most painters say that concrete floors are the highest risk surface to paint. The reason being is because it will often peel. It's a great idea to paint it because it will look nice. The real question is how long it will last.
There are some things to consider when painting concrete floors. The first, is it a new floor? If it is new concrete, you want to give it time to fully cure.
The second is the preparation of the concrete. If the floor is in a garage or basement, it can be stained with other materials. It can be mechanically ground or etched so that the concrete is accepting to a paint-like material. It is quite a job to mechanically grind the concrete with diamond blades which create a lot of dust. You can also do it with chemicals, you use an acid to open up the pours, but it is a tough material to work with. It can cause burns and it is not good to inhale. But the prep-work needs to be done very well.
Some of that prep-work entails cracks in the floors and leaks. Cracks need to be repaired with the right material because concrete does expand and contract so it will just crack again.
The third thing to consider is what product to use. You can use a paint-based material to coat the floor, but this tends to peel. You could use a stain which stains the concrete, but what people don't like about stain is that you may pick a color, but once applied it can be a different shade, similar to wood stain. The third material you can use is two-part epoxy which gets very expensive, but it is supposed to last longer, it does have a high odor level and you have to be very careful working with it to get the type of finish that you want.
There are also specific considerations for the painting process itself. When painting the garage or basement there is going to be humidity and moisture. Then you are going to get peeling. We advise, if you are going to do it, do it before you sell the house.
Given all of the considerations to the preparation and the painting itself, I would not recommend painting concrete floors. In fact, even as a professional, I would not paint a concrete floor at all. I'd repair the cracks, but that is it.
If you want more information on concrete floors or basement waterproofing, contact A1 Foundation Crack Repair.