What Am I Riddles

Question: What is black when you buy it, red when you use it, and gray when you throw it away?

Question: I have a name that's not mine,
and no one cares about me in their prime.
People cry at my sight,
and lie by me all day and night.

What am I?

Question: I drape the hills in white,
I do not swallow, but I do bite.

What am I?

Question: What runs around the house but doesn't move?

Question: What grows up and down at the same time?