Risk free way to ask out a colleague?

Follow up to my previous question (might want to read that for context first, here: http://www.ehelp.com/questions/10476476/does-they-new-guy-at-work-like-me)

Okay, so how can I ask him out out without it backfiring if he says no?

For instance, is there a way I could ask him out but make it sound like I could just be asking as a friend/colleague - in case he turns me down, it can make it seem like I was never actually asking him for a date in the first place?

Any advice you can give would be much appreciated!!

You can tell him that you are going for dinner or to cinema with some friends and he can join if he likes.