Whiteboards are a place where you can use boardwork.
You can write on whiteboards using dry erase markers. These typically come in different colours, just be careful not to use a red pen on top of a black mark because the red pen will absorb some of the black ink.
Leaving whiteboards clean for you colleague is common courtesy.
If you (or your idiot colleague/student) accidentally writes on a whiteboard with a permanent marker, use a non-permanent marker to write over the permanent ink; the mix of permanent/non-permanent ink can then be removed conventionally.