I am a fairly new quilter and have a question. My pieced top (around the world), has several colors in it. I am afraid if I choose the darker color to quilt, it will really show up on the light fabric and vise versa. Is it ok to use invisible thread on the top? Is invisible thread hard to work with?

I would never suggest a new quilter to try invisible thread. Is very hard to work with. How big is the quilt? Very often, depending on how dense you quilt it, the quilting doesn't really take away from the piecing. It just compliments it. If you choose a neutral color you may not even notice the quilting.

I agree, the invisible thread is not made for hand quilting.
The one I tried broke very quickly and the tangling was quite bad!
For a multicolored top you can use a neutral color that blends like a light grey or a natural tone. Another option is multicolored thread with lighter shades.

Varigated thread is another option :D:D:D

I like using a neutral (either off white, or light gray).

Thank you for the suggestions. I'll try to find a neutral color. I plan to machine quilt. Probably meandering. The quilt is a lap size.

Try Bottom Line from Superior Threads. I use it for everything, usually the pale beige or light green; very, very thin and disappears in appplique, machine or hand quilting.
http://www.superiorthreads.com

I use Bottom Line in the bobbin all the time. Do you use it for the top thread as well. I love the way it 'melts' into the fabric.

My Bernina takes it top and bobbin
Jems will only take it in the bobbins; I use Aurifil then as the top thread usually.
I have a box of Coats and Clarke, Isacord, Gutterman and other mfgrs that I sell to anyone who's interested
Now it's only Superior Threads, mainly Bottom Line, Aurifil and
Presencia

i had such a terrible time with it in my longarm that i will never use it again. and it took me forever to find the right tension for regular thread when i was finished.

edit: it was Superior.