Colors are applied either as dyes, which are absorbed into the fibers, or as pigments, which adhere to the fabric surface. Usually both are reasonably colorfast. Some colors however, are totally unserviceable, not fast in either water or drycleaning solvent. Pigment prints and metallic prints are held to the fabric with an adhesive, and may wear off over time, from wear as well as cleaning. Some dyes fade on exposure to strong light, especially sunlight, but sometimes strong artificial light as well.
Some dyes change color on exposure to combustion gases present in the air.
In addition to fabric and color, you must also be concerned with how buttons, beads, sequins, and other decorations and fasteners will hold up to drycleaning. Most troublesome in this respect are buttons and beads made of polystyrene, which softens or melts on exposure to drycleaning solvent. Beads and sequins may be covered with a thin coating of color, which may come off during wear or cleaning. Beads or sequins may be merely glued on and come off during wear or in cleaning. Trim that is sewn on with a single continuous thread may all come off if the thread is broken.