Racism is not defined as "individual acts of meanness." All "-isms" are defined as a SYSTEM which advantages one group over another (sometimes this "advantage" is defined as "power"). Just as sexism advantages men over women and classism advantanges those "who have more than enough" over "those who do not have enough," racism advantages people of white European descent over people of color. The term "people of color" is a political phrase grouping folks based on such categories as marginalization in society, ethnic minority status, and lack of power in the larger social structure of laws, politics, land owning, corporations, etc., not actual skin color, or actual "numbers" as the word "minority" might imply.
These ADVANTAGES or "privileges" are best defined by Peggy McIntosh in her paper , "White Privilege: Unpacking the Inivisible Knapsack." http://www.nymbp.org/reference/WhitePrivilege.pdf They are not asked for, often unknown, and notoriously not noticed, however, they DO EXIST. Power and privilege is created within a societal system. Those that have it, don't typically notice unless it is pointed out. Those that do not have it, know all too well what it looks like and what they can and cannot do or have access to.
A SYSTEM is when cultural norms benefit one group over another, as when Christian observances are marked on a calendar (or officially taken as a day off), but the same benefit (privilege) is not given to Jewish observances.
A SYSTEM is when laws (or rules) directly benefit one group, and not another. Laws are particularly problematic because their impact can continue for generations. For example, if your ancestors were taken from their land (African), or their land was taken from them (Native American), or they were not allowed to buy land (people of color) because of "red lining," then the advantages of owning land, building equity, using that equity to create a business or send a child to college, were not available. The impact of land owning (or lack of it) trickles down from generation to generation.
This video has an excellent summary of some legislation that advantaged people of white European descent, while disadvantaging people of color - and land owning is only a small part. https://www.youtube.com/watch?v=YFjKQVZLk1g
