I'm having issues...

I cannot figure out why I can only adjust pitch on certain regions in GarageBand. I can tell it has something to do with the color of the region but I don't know what the different colors mean... I can adjust pitch on purple regions but not on orange ones. I'm getting very frustrated.

I've been brainstorming and I'm going to find plants that are plants but that are either very manipulated by man or indoors and see how that changes their speech.