Hinge choice should compliment the door hardware finish
The hinges for exterior inswing and outswing doors are different for security purposes. The exterior doors either have non removable pins or a security tab on outswing doors. Inswing doors need neither of these features.
The hinges for the new prehung doors should coordinate with the color finish of the door hardware knobs and levers. Most people keep a metal tone that is fairly consistent throughout the home. The hinge manufacturers have finishes that coordinate with the hardware manufacturers but they are not manufactured in the same exact way. The finishes coordinate but are not exact. That is the only choices available and chances are that if you were never told you would never notice the slight differences.
The size and shape and hole patterns vary also but here we are just choosing the finish. The hinges come only with prehung doors ordered not when just a slab is ordered. If you are retrofitting, you will probably use the existing hinges. If you are wanting new hinges, then you will need to take 1 hinge with you to make sure you order the exact size, hinge pattern and corner radius.