How does color choice differ between choosing your own colors or having an interior designer choose them for you ?

A person who make a color choice without interior designer just refers to the color itself. It means when he goes to the shop to buy a color to paint his room, he just picks up the color thinking it can be okey and he buy the full amount in order to paint all room. Interior designer will look firstly at the orientation of the room (how much sun you get during the day), secondly he will look at the furniture (style, color etc), thirdly he will ask your preferences of course. And finally instead of buying full amount of paint, he will pick up several (can be one color but in several hues) to paint several parts of the room. This is done in order to understand how the color will look like in your particular home. Color you see in the shop can differ a lot from the same color in your room.