Prior to "race" as a concept being invented to justify colonial atrocities, xenophobic discourse hinged on things like religion, diet, and climate rather than blood. Like before they got the idea to start measuring skulls and whatnot they thought that warm climates and flavorful food would make people "base and bestial" (I'll add that this is a weirdly persistent reactionary idea that you still see popping up today by people who cram handfuls of raw, unseasoned ground meat down their gullet as a performative display of purity and masculinity) and before that it was purely religious ideas about all non-christians being little more than demons in human skin or the like.

Racism developed after the conversion of indigenous peoples to christianity, as Europeans needed a new excuse for why they were continuing to enslave and slaughter them as the religious subjugation and conversion arguments they'd relied on stopped being useful.