Why are guatemalans so racist?

why i am asking this is that i was called a white indian by a guatemalan because he said i have an eyes of an indian and the skin of a Norwegian and then he called me a weird word called a menchu i do not know what the hell a menchu is and personally if guatemalans are part indian why are they dissing there indian side of the selves and when he refers to white a light skinned mexican lady comes up and a mexican who calees me a mamon and a gum seller and i am from uruguay so i dont what they say