You can find a kitchen towel just about everywhere nowadays. The cheap and obvious place to purchase is your local supermarket or Target store. Keep in mind, the local places are going to have cheap weave towels that usually have a tacky floral print or lame color scheme.
You can also find expensive high quality towels at Crate and Barrel or Williams Sonoma. These trendy places are great for decorative towels that hang from the stove but they aren't great to cook with.
If you are a serious chef then why not stock your kitchen like one. Most restaurants use plain white towels so I suggest getting some for use in your kitchen. White towels are cheaper and it's easy to tell when they get dirty. I shop for my Kitchen towels at Sam's Club or Costco where you can find 10ct bags of them on the cheap. It's great to have a drawer full so you can change them often during cooking on an as need basis. The warehouse clubs sell to most restaurants so you are getting the same towels the chefs are!
For more on towels and how they may help you cook up some romance in your kitchen, don't miss this week's Forking.