riddle again retared ?

[Angelea]

What is black when you buy it, red when you use it and grey when you throw it away?

 

[dragon]

a newspaper

 

[hope-marie]

charcoal





easy.

 

[Hanna H]

you're retarded because you can't even spell retarded.
:[

 

[Paolo S]

charcoal
black-store bought
red-flames
white/grey-used