Colleagues present same data analysis for years, each time with different "framing". Ethical? I have seen colleagues present the same data analysis multiple times over several years.

By present, I mean two things. First, present the work to other faculty and PhD students in departmental seminars and informal brown bags. Second, I mean present the research to journals by submitting it for peer review.

Each time I see the work presented, the data analysis is rather similar to the last time I saw it presented. But what the study is "about" changes significantly, sometimes using different theories and claiming to have a new research question.

What does not change is that the paper claims to test hypotheses derived from whatever theory they are using. The hypotheses keep changing, but the analysis doesn't change.

The changes to the theory and research question are explained as having the previous paper rejected at a journal and needing to change the "framing" of the paper or responding to reviewers who "didn't like" the way the analysis was presented.

Is the behavior of my colleagues ethical?
What venue are they “presenting” the work in, and does it carry an expectation of originality?

Publishing multiple minor variations of the same piece of work would indeed generally be considered as unethical, or at best borderline-ethical “salami-slicing”.  That’s because publishing carries an expectation of originality/novelty: you’re not supposed to publish the same work twice.  This is deeply entwined with the ways that publications are used as a metric of productivity.  However, it sounds like this isn’t what’s happening here, if your colleagues haven’t succeeded in publishing the work.

Whether presenting multiple minor variations of the work is ethical depends entirely on what venue they’re presenting in (major conferences? informal workshops? the departmental seminar?) and whether it has an expectation of originality like publications would.

This varies between fields and subfields, and between conferences within subfields.    In pure maths (at least in the subfields I’m familiar with), conference presentations have no expectation of originality.  You can present the same piece of work every year for a decade, and people won’t be very excited or impressed, but it won’t be considered as unethical.  In computer science, on the other hand (again, in the subfields I know), presentations at major conferences are like a smaller version of a journal publication, and as such, are explicitly required to be original: re-using material between them would be unethical.  But in less formal settings (e.g. local workshops), again there’s no such expectation of originality, and re-use of material (with or without variation) is fine.