I dont use the visualization on the players.I spend most of my time playing music myself and playing along with tracks.I have seen what you are speaking of on several players.
I am trying to find more info on what colors are associated with different tones.I know when I experience the colors while playing there is a certain kind of sound that makes it vivid to me.I thought it quite strange but pleasant.
There is a sound that I feel is my sound if that makes any sense.It is the sound I want to hear when I play my electric guitar.It occurs when I have my guitar effects pedal on acoustic and the mids all the way down and the treble and bass all the way up with a slight reverb.It is a sound that has it's own soul to me.