If you have straight, thick hair, unless it's damaged or very dry, it should stand up reasonably well to any type of process. On the other hand, if your hair is coarse and wavy or curly, it may look dry or damaged, even if it isn't. So, it's a good idea to use the gentlest possible method to avoid increasing its damaged appearance. Wavy or curly hair tends to be more porous than straight hair, so it absorbs dyes more quickly. If you color at home, keep this in mind, and always do a strand test to get the timing right.