Removing color from notes

I have a four part chorale on two staves. For some reason, all the notes in the tenor line that are above the staff are colored (middle C and above). Why does this happen and how can I turn it off?.

Actually, in trying to deal with this problem, I did find the colored note plugin. I managed to color ALL the notes and then couldn't figure any way to un-color them except by using the Undo command. So, I'd like to find out how to do that, too.