We all have non muslim colleagues from workplaces, schools, sports centres and the like...[unless you are from Saudi]..but are these colleagues your friends?
I'll speak for myself.
My non muslim colleagues are NOT my friends. My muslim colleagues are my brothers and sisters.
What habbits and values we pick up from non muslim colleagues is, I feel, an individual choice, which must be measured against Sunnah and Quran compliance/compatibility....(how well,if @ all they do, do these values fit in with my way of life..[ ISLAMIC]?)