any way to easily change the color of the progress bar and visualizer?
Only by editing the .xml file.
The parts you need are in the last 3 sections.
The colors are in RGB format (0,0,0 = black / 255,255,255 = white).
If any of the settings has a 4th value (x,R,G,B) than x is a transparency value from 0 to 100.