The fact is the Spanish were in Colorado long before the white man set foot here.  Where on earth do you think the name "Colorado" came from in the first place - it sure isn't English or French.  Those "Mexican-American" communities in Southern Colorado are left from the original settlers, who were Spanish, and have been here a lot longer then the "dominant" culture you seem to love so much.  The invaders are both the white folk and the Spanish but if first invasion means anything than the Spanish got here first.