Most dust and dirt in homes is actually white or light in color. Some people think that dark colors hide more. They might hide a spilled liquid, but patterns and lighter tones are better for hiding dust and most dirt.
You obviously might want to steer away from ivory or white carpet if you have kids or pets, or if you keep your shoes on in the house, but a nice neutral with a patern can hide the most. Fabrics or carpeting with patterns also hide more as your eye goes to the design, not just the color.
I have a client with a black lab. She likes her house very clean. We were deciding on a stair runner so we actually got some dog hair and put it on the choices. We picked a pattern that hid the hair the best.
Another client has 3 white pets. We tested fabric chices against white cat hair.