What do you mean be "rainbow". The curve of a rainbow or the diffrent colours. I sometime get a green or red bar on the top of the pictuire. The colour depends on the background. It disappears when I pause the tape and resume. So I figure that this is also a head problem. Never figured out if it actually is something that can be fixed since this is something more people have reported. The deck is very old, so I have not so much faith in it.... I bought a Digital 8 player and see if I can get better results.