A long time ago I installed blue led lights under the dash and the doors. I kept it like that for some time but then decided to switch back to stock or led white. I did switch to white led lights but if someone wants to see what it looked like here are some pictures of what it looked like:
The bulb type that can be used for this is T10 or T8 as pictued here:
Post pictures of your bmw projects, even if its not 7 series, no matter how big or small, we would all love to see it.