James 2:1 says, My brethren, have not the faith of our Lord Jesus Christ, the Lord of glory, with respect of persons. James called on those who had put their faith in Jesus Christ, and were therefore brothers and sisters in Christ, to not treat people differently because of who they were in the world. I believe this would apply both materially and ethnically. God does not see one ethnic group as superior to others, and neither should we. God also does not judge people based on their material wealth, and neither should we.
Verse two adds, For if there come unto your assembly a man with a gold ring, in goodly apparel, and there come in also a poor man in vile raiment; James then continued by speaking about a rich man coming into an assembly of Christians and a poor man coming into the same assembly. I believe we can apply this to people of different ethnic groups as well.
Verse three continues, And ye have respect to him that weareth the gay clothing, and say unto him, Sit thou here in a good place; and say to the poor, Stand thou there, or sit here under my footstool: James added what if they treated the two men differently, given the rich man a place of honor and relegating the poor man to the back. This was treating them differently because of their worldly status. We as Christian should never do this.
Verse four concludes, Are ye not then partial in yourselves, and are become judges of evil thoughts? James then asked if they did this, had they not become judges and partial to people because of their status and therefore guilty of evil thoughts. Anytime we begin to judge others because of who they are in the world, we become guilty of evil thoughts, no matter what we base this judgement on.