Good Riddles

Question: A man named Tom goes to a party. Him and three guests go into a back room to play some games. A few hours later the four of them are discovered dead. One was beaten with a shovel, another had a drill bit in his head, and the other had been clubbed to death. Tom has no marks on his body.

How did he die?

Question: How can you make a TV, a bed, a dog, and a car liquid?

Question: When do you go at red, but stop at green?

Question: 100 feet in the air, yet its back is on the ground.

What is it?

Question: I'm red, blue, purple and green.
No one can reach me, not even the queen.

What am I?