I can only address my personal experiences. I've been traveling to Germany since the 80s. Obviously, mostly in the west until the 90s.. I have driven all over, taken trains, busses, planes, etc. I can not think of one racial incident that I have experienced. There are counties in my own state where I often feel uncomfortable, but I have never felt that way in Germany.

I wish I could remember all of the hundreds of Germans I have met who have extended warm welcomes and I have worked with, dined with, gotten drunk with, laughed with. It is truly one of my favorite countries on the planet. That being said, like anywhere else, be aware of your surroundings and know where you are. Although, I have felt pretty safe stumbling through Berlin at dawn after a crazy night.