Give your new hair color a chance to settle in. Hair coloring is a tricky business. It usually starts out vibrant and then tones down after time.
If you are able to speak your truth in love, you probably won't have any problems or hurt feelings.
I dyed my hair red once. It was as bright as a fire truck day 1. I was nearly devastated but in about a week or so it was the color I was going for. It just needed time to tone down.
Manage your expectations about your hair color and let your friend know how you feel about it.
I'm curious as to how you would handle the situation if she were not a friend. If your friend isn't a licensed hair technician, she may not know everything needed to fix your problem or may have done something unknowingly. The good news is that hair grows and it will grow out soon enough. Good luck to you.