I read a book not too long ago, called : "The Sky So Big and Black" by John Barnes. In the book they talk about a devasting solar flare, (for lack of a better term) that decimates a Martian colony. Does the Sun ever get really bad hiccups?

Yes. During the sunspot maximums you can get very impresive 'X-Class' coronal mass ejections. Quite a few hit us over the last few years. Which is why Aurora have been seen in more southerly latitudes.

I doubt a large CME would kill people on Mars though. Chalk that bit up to Fiction.