How can my colleague use our joint results in his PhD thesis?
Don't worry, be happy (and be truthful). There's nothing wrong in including in one's thesis stuff that you didn't do yourself, as long as the delimitation between what the candidate did and what others did is clearly marked. And by that, I mean no lies, but also no half-truths either.

Basically, the presentation will thus depend on the interaction between you two and his part in the analysis (which ranges from “nothing” to “he suggested ideas that I tried” to “he ran my code himself”). In the first case, he could say:


  As part of project X, I sent these results to Dr. John Doe at Big U. for him to perform his widely acclaimed topological Bayesian half-filter analysis. This analysis revealed that …


There's nothing wrong with presenting results obtained by others from your work, as long as they shed light into the phenomenon you're studying. I once had a student who published a work, which was built upon by another group during his PhD, and he presented this at some length (and critiqued their extension) in his thesis. That's part of the whole story.

If the collaboration was closer, just make sure the thesis clearly indicates its nature and the contribution of everyone. Then, no fuss!