Are маркерная доска and белая доска both standard terms for a whiteboard, or is one of these more widely used (in speech)?
As a native speaker, I would probably go with the former one. One never refers to the color of the board, you just say "доска" as in "в аудитории есть доска", and you could further specify it as "доска для маркеров (или маркера)" or "доска для мела". The term "белая доска" requires some explicit thinking before I remember that this seems to be the color you use a marker on.
As a native office citizen I would go with "доска" or "доска для рисования" or just translate as "белая доска". Never have used "маркерная доска". On the other hand I mostly work with foreigners and I used to say whiteboard without translation even if I speak in Russian. Like "Там есть вайтбоард?". But this can only be true in office environment since you do not expect to meet any other board in the meeting room. Maybe in some educational rooms you will need to define if you need markers or chalk.