The idea that blacks are people of color comes from the time of the Civil War.
The United States fought the War against the States of the south because the States of the south were going to secede. If they seceded, the U.S. government would lose the revenue they taxed from the southern States. They couldn't take the idea of revenue loss, so they fought the war to maintain their taxes.
The people wouldn't have backed the North if they knew it was over taxes. So the U.S. government had to provide a different reason. They deceived the people into thinking that it was over slavery. To make that deception real, they really had to completely act the part. The question was, what do we do with a bunch of freed slaves who had no "standing" because they were slaves?
The answer was to make them slaves of the government. They did it by enacting the 14th Amendment which makes people "citizens" (slaves) of the Federal Government. By rights, government can't force anyone to become slaves or citizens. But the 14th Amendment makes a way for it to be legal-like.
Legal-like.
Color of law. Looks like real law, but essentially isn't. Just has a "color" that looks similar to the lawful color.
Color of law.
The citizens of the U.S. government under the 14th Amendment only have rights that the government allows them. Of course, they can fight for those rights, and often get them expanded - other times they might lose some.
Non-citizens, i.e. people, have unlimited rights. Anybody who wants to become a citizen of government (because he is deceived into thinking that he is better off letting government dictate what rights he has) can become such. He is such under color of law, because he always has the right to maintain his position as a human being outside of such citizenship.
Blacks (or anyone else) who don't know this, but become citizens of the U.S. Government, do so under color of law. Because blacks of civil war times were the first - they didn't have the knowledge of how to be free men - they became people of color.
These days, most of the rest of us live as 14th Amendment citizens of government as well. Most of us are unaware of how we can be non-citizens, and live as free people out from under the thumb of government and its taxes. The point here is, we are mostly all people of color. Listen to Bill Thornton at
http://1215.org/, or Youtube search on his name.
Listen to Karl Lentz (Youtube search on Karl Lentz common law) to see the practical ways to use Bill's information. Karl is a little hard to understand at times, because most of the time he is throwing out information that works if the circumstances are exactly as he depicts them, while at the same time he is throwing it out in such a way that it might be able to be used when circumstances are not exactly as he describes. He will tell you right out at times, that you need to use his stuff with common sense, adapting it for the circumstances you happen to be in.
Youtube search on Richard Cornforth. You can find all about the laws you wished you knew (mostly court cases) that could set you free if only you knew they were there. Check his site at
http://voidjudgments.com/.
The point is, we are all people of color... except for the few of us who have stepped out from under citizenship into freedom. The reason the term is applied to blacks is, the place the term was first used was with the "freed" slaves of the Civil War times. And most of them were black.