My iPad dropped and the screen turned red. What do I do to restore it?

Most likely the iPad has been damaged and you will need to take or send it to Apple and pay for replacement. You can try giving it a firm slap on the back; that's corrected the problem for some people. If not, then a replacement will be necessary.

Regards.

Try holding the home button and the lock button down. If it is the software then it could reboot and be fine but if the hardware is damaged than I would take it to apple.