Playback is upping the brightness of my video.

I just recently bought Movie Maker Pro. I'm trying to edit a speed paint for youtube and for some reason even when I don't have any filters applied, the brightness just gets boosted way up whenever I play it back and watch. Is this just how the playback works, and it will be uploaded normally, or will this affect the final video? If so, how to I fix this?

An additional question about audio, how do I make certain audio layers quieter? I haven't added my voiceover yet but the music is way too loud and even when I use the little volume button on the audio tab, it doesn't seem to make any difference. Thank you.