Yes I think racism is rooted in economics.
In particular the slave trade which lasted for some 350 years involved the capture,forced transportation, enslavement,humiliation and oppression of many millions of black people on two continents.
These people were treated with the utmost barbarity...mass murder,thrown overboard,crowded into hell holes,separation of families and loved ones,torture,branding ,and much much more.
Those major powers like Britain and the USA that were up to their necks in the blood and gore of the slaves had to give some kind of justification for the slavery of millions and thus despite 1500 years of christianity systematic racism was unleashed to try to justify that which could not be justified.
Those who made millions out of the slave trade and the sweat of the slaves promulgated myths of racial inferiority and superiority,africans were declared to be less than human,they were good for nothing except beasts of burden etc.
Capitalism as Karl Marx wrote was born dripping out of the sweat,blood and gore of the african slaves whose labour in the New World was to build the foundations of our economic system.
It is interesting to note, as an afterthought, that when Marx was asked about his favourite historical character he answered immediately with the name of "Spartacus" the leader of the Roman slave rebellion.
ifor