I would think
that a colony on Mars,with the exception of a very close or direct hit by a large object, would be much safer than a similar hit on Earth. Part of the problem of a huge hit on Earth is compounded by our oceans and atmosphere, the oceans tend to create giant tsunamis and our thick atmosphere is a wonderful conductor of heat.
My guess would be damage on Mars from a huge hit would stay largely confined to the immediate area with the exception of maybe a dust problem.
Art