So if you're non caucasian it's a big NO?
I have childhood friends who came to the US during the Yugoslav wars in the 90s. When I mentioned them my coworkers they would quickly point out the last name was Muslim and not Serbian. Also they would point out the one or two Albanians that worked with us.
In Europe, discrimination, when it happens, is usually based on national or religious differences. All wars Europeans ever fought were over national or religious reasons.
In Serbia generally racial discrimination is not present, nor is a topic of any conversation in media or society (certainly not to any extent like in US). There was a war between serbs and bosnian muslims and serbs and kosovo muslims (note national/religious connotation) some 20 years ago, and some people may have 'hard feelings' about it, but in general that's the end of it. Still, being a Muslim in Serbia is IMO a 'better' experience than being one in USA (maybe also because 5% of population of Serbia is Muslim vs ~1% in USA).
Discrimination based on nationality is a thing, but it is very much something that varies a lot in Europe. To generalise it as one of the top reasons for discrimination isn't quite right in my opinion.
That said, it's the type of discrimination that is the most prevalent, simply because that's what most people deal with.
However, I think that in day to day life skin colour may be more noticeable than other types of discrimination, simply because it is easier to make out.
While in some places discrimination of certain nationalities or religions is certainly common place and as such might seem like it is the predominant form of discrimination, discrimination based on skin colour is also present. Maybe to a lesser degree, but it is present everywhere.
The simple truth is that the "better" experience will be the one Caucasians get.
Perhaps we can agree that in Europe, national/religious discrimination is probably an order of magnitude more prevalent than any other form of discrimination. From my experience and in practical terms, I would even put social/economic/education based discrimination before skin color based one.
Those individuals who during the 1990s were the most ardent supporters of the ultranationalist politics that paved the way for the genocide in Srebrenica—for the ethnic ‘cleansing’ of Muslims in Bosnia and Herzegovina as well as Kosovo—are in charge today, too. Since the time of the socialist state’s end, there have hardly been any powerful political actors in Serbia who did not in some way advocate some idea of a ‘Greater Serbia’.
There is a clear continuity of nationalist politics that has more or less been going on since the nineteenth century, and the dominant line of political thinking in Serbia throughout history has mostly been nationalism. The essentialization of Muslims as the ultimate ‘Other’ has been one of this nationalism’s main pillars. On the one hand, Serb converts to Islam are in some way worse than ‘born’ Muslims for most Serbian nationalists. There is the popular saying ‘a poturica [convert] is worse than a Turk’, and the derogatory term poturica applies to all South Slavs who have accepted Islam—including Bosniaks and Serbian converts.