As a child who had been homeschooled through 8th grade, entering high school at a big public school was a huge adjustment for my son. He made some really nice friends right away, joined some organizations and was on his way to a rewarding high school career.
Soon after school started he wanted to grow his hair out. That was fine with me. Then he went from wearing his khaki pants and plaid shirts to black jeans and black t-shirts. Then black coats. Then the black eyeliner started. Goodness! I didn't know what to say to that, but he actually looked great in the eyeliner! And I still don't know how he learned to put it on so well!
The end all beat all was when he asked to dye his hair jet black. His hair was dark brown to begin with, but he wanted it BLACK! That is when I called my friend to see what on earth I should do. This was my son wanting his hair dyed, not my daughter. She had already raised two teenagers and she is the one that said "Let him do it. There's a lot worse things he can be doing at his age. If you fuss, he'll fight you on it. Just let him do it, and let him get through this phase. It'll pass." I had another friend who told me her son went totally goth in high school and college and is now a clean, cut wall street broker. So there was hope of normalness after the "goth era".
Sure enough two years and four months after his first day of high school my son came bounding down the stairs asking me to take him shopping. "What do you need?", I asked. "Colored clothes. I'm sick of wearing all this black." That sentence was music to my ears.