Colleagues are indeed just colleagues, however there are a lot of other aspects to it. I am happy to have a friendly atmosphere with colleagues that I work with and that's enough. Becoming friends (and I mean actual friends) will require a "spark", at the end of the day there generally 2-4 people that you can call friends during your life, everyone else are just "pals" that come and go, which is totally normal as far as I see it. Throughout working in different places, countries, companies - the is only one person that I keep in touch with on a regular basis, but I still can't really say that he is an actual friend. I've recently been posting some stuff related to peoples general outlook on things and life, what is really important to become friends is to have a similar "life goal" (so to say) and overall values.