Should I be worried about this bump on my back that is changing colors and itchy?

I have a pretty small pea sized bump on my back. I’ve had it for probably a year saw a doc once for it and they said it was just a bump. But, every so often it itches and it changes colors too. It can be my skin color, or tan/brown to a light red. It doesn’t really hurt unless I scratch it too hard. Anyone know what it could be?