Answer:
I can be any color you can imagine. You see me in everyday life. Look around, you can probably see some of me right now. What am I?
What has four wheels and flies?
I am a small paradise surrounded by dryness and heat.
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
I am a mountain at night, meadow at day. What am I?
Why did Superman flush the toilet?