Help the House!!!

So I've been planning for 2 years how to organize my home to be more efficent and non-cluttered. Planned on what colors I want each room and the themes....you name it I've planned it. Then it all comes to a screeching halt. I'm afraid to paint the walls because I think I might now like the color or I will be stuck with this same theme/color forever. Yes its only paint but I think I need the eye and help of an interior designer. lol. I want my home comfortable, modern, clean lines, and for it to have a warm cozy feel. I want the bathrooms to be a relaxing haven for escape. But I want all rooms to be neat, organized, a place for everything and everything a place. So just how do I achieve this???