Then how would you explain nature being 'unfair'.

Race exists due to nature and we use it to denote distinctions in our collective race.

We should celebrate our differences, not pretend they don't exist, or are merely humans being derogatory to each other.

While I agree with your conclusion, unless by "nature" you mean "human nature," the statement > Race exists due to nature is absolutely false. Race is a cultural construct and has little to do with biology or national origin.