Can a slave be white

Yes a slave can be white, or any other racial or ethnic group. There were slaves mentioned in Bible times, in fact, and while most were from non-white groups, few were black. In colonial times, poor people (nearly all of whom were white) were sometimes sold into indentured servitude. They had few rights and had to serve their master for a number of years; in theory, they would be taught a trade in exchange for their labor, but this did not always happen.