Final answer:
Temporary hair dyes or sprays are colors that coat only the surface of the hair shaft and cuticle, creating a physical change. They are easily washable and do not permanently alter the natural hair color.
Step-by-step explanation:
The colors that coat only the surface of the hair shaft and cuticle, creating a physical change, are temporary hair dyes or sprays. These products sit on the outside of the hair and do not penetrate into the cortex or medulla. Examples of these colors include washable hair chalk, temporary hair sprays, and colored hair gels.
Temporary hair dyes and sprays are often used for special events, costume parties, or when someone wants to change their hair color temporarily without permanently altering their natural hair color. These products can be easily washed out with shampoo, allowing the hair to return to its original color.
It is important to note that these temporary colors may transfer onto clothing or pillows, so it is recommended to take precautions to prevent staining.