Depends on which part of Europe. In the more diverse parts, nobody would bat an eyelid (even if border police might profile you).
EU Eastern Europe, you might get funny looks but it's still not an extraordinary situation to have various shades of skin colour (e.g. Syrians, various Central Asians are migrant workers in a few of the countries in question; a lot of e.g. the Balkans are on a palette of skin colours).
Non-EU Eastern Europe (referring more to Belarus than Montenegro here), might get casual racism.
Nobody will throw you in jail in indefinite detention in another country with no human rights because of your skin colour, beard, tattoos or anything of the like. Other than of course the usual suspects of Belarus, Russia, Azerbaijan and etc. who could for any reason.