The purpose of this study module is to review the principles, practices and theories of hair coloring. Precautions: To ensure the safety and accuracy of product use for coloring services that you perform, please consult the product company and their published instructions and information regarding their formulations. Never take for granted that you already know how to prepare or process hair coloring products that you are unfamiliar with. To do so could cause injury to yourself or your client. Also, keep in mind that companies sometimes change their formulations. This may or may not effect the way you mix and apply their product. However, to be abreast of any changes, you should establish the practice of reading all packaging enclosures, labels and instructions as part of your customary preparations prior to performing color services.