It's (a purple pen). It isn't (a yellow pencil). Is it (a purple pen)? Yes, it is. No, it isn't.
It's (a blue circle). It isn't (a red circle). Is it (a red circle)? Yes, it is. No, it isn't.
It's (yellow paper). It isn't (red paper). Is it (red paper)? Yes, it is. No, it isn't.