In choosing a color, lighter colors tend to disguise lint and dust, show dirt (except stain resistant carpets), and make a room seem larger.

Darker colors tend to show lint and dust, disguise dirt, and make a room seem smaller and cozier.

Neutral tones that mimic such natural elements of wood, stone, marble, or slate are best able to disguise both soil and lint.

Warmer colors such as reds and yellows reflecting the glow of sunshine, while blues and greens have a cooling effect.

Additional thoughts...
Depending on your decor, there is no rule that carpet has to be uniform throughouta dwelling. When selecting a solid carpet to coordinate with patterned upholsteryor drapery fabric you could find a complementary shade of the dominant color instead of an exact match, adding interest.

Lighting sources will change the look of your carpet's color. Natural sunlight from a window will create a different effect than the overhead light of a chandelier, or the indirect light of a lamp. Viewing your sample at different times of the day in the room it will be used will help you decide if you've selected a color that looks nice regardless of the light source.

In selecting a texture, it establishes the character of a room...from the formal look of cut pile velvet saxony to the casual look of berber. The texture of carpet allows you to express your personality and lifestyle. A heavily textured carpet will also help hide footprints.