If they are decorative in the sense that they complement the colors or décor of you bath but you plan to use them everyday, then you'll for sure want to buy quality towels that are soft, fluffy and colorfast.
The main disadvantage of a wool rug is that some rugs are not treated with a colorfast dye, so the rug will fade if placed in direct sunlight.
Look for fabrics that are durable, have a good appearance, hold shape, tailor well, go through multiple cleanings and are colorfast.
Soy protein isolates were used with printing ink and paper in the printing process to bind the inks and make them colorfast.
With colorfast additives, wool fabrics can now be placed in direct sunlight without the former issues of color fading.