Hi Emmeladelyn,
I don't think " kill the time" is only colloquial and rarely used in writing.
To kill the time : do something to keep yourself busy while you are waiting for something to happen.
To pass the time : do something to stop yourself being bored during that period; do something to keep yourself busy while you are waiting for something to happen.
To while away the time: spend time in a relaxed way because you have nothing to do or while you are waiting for something to happen.
To sum up, all these three sentences can be used interchangeably.
Best Wishes