New tank - 2 questions

I've had experience raising baby bass and northern pike (what I call
"natural" fish)  That I would catch from a lake in Wisconsin. I've also
raised matted pairs of Angle fish. My goal was to always create a "normal"
environment for the fish (natural looking plants, rocks, etc..).

To make a long story short, my daughter wants to get into raising tropical
fish. She's decorated the tank (not to my taste) a bit "wild". Bright green
and pink rock. Orange and glow green plants, and a piece of purple brain
coral (I believe it's fake).

My first question (actually my daughter's) is "is there a blue background
that I can attach to the back of the tank, that would adhere and reflect the
light well (as opposed to the natural scenery I have on my tanks).

Secondly, which kind of fish can I steer her towards buying that won't
"freak out" by being in such a "colored" tank?

Any advice is appreciated.
Thanks!
Phil