My phone has a bright rainbow of colors going down in several lines. Can this be fixed or do i need a new phone?

That is most likely hardware not software... Needs a repair! Schedule an appointment online so you don't have to wait

It's usually cheaper to get it repaired at Apple especially if it's still in warranty.

You will need a new phone or a very costly repair. Sounds like it's the mother board. If you dropped it with a crack then it could potentially be fixed as a screen repair

Yes