I am no expert in Latin by any means; however, my grandmother studied the language. In Latin, there can be multiple translations of a single English word, with each having its own meaning or context.
In Latin, the words for the color black is ater, atra, or atrum. The Latin word, niger, is the denigrate form of black. Niger's Latin etymology is denigrare, which means 'to make very black; defame' or nigrare, 'to blacken.' Here are my sources.
'Whether you want to translate a short English phrase into Latin or a Latin phrase into English, you can not just plug the words into a dictionary and expect an accurate result. You can't with most modern languages, but the lack of a one-to-one correspondence is even greater for Latin and English.'
Regardless of how you look at it, 'nigger' (or its variants) is not an acceptable word to label people of darker skin tones. It is offensive.
We all know, of course, that black isn't a color at all. It is the absence of color. Of course, there aren't many people on this planet who are truly black. Since we were the first humans on this planet, we should call ourselves 'The Originals.'
On a somewhat related topic...
Divide and conquer via the use of labels or another (silly) reason we still aren't united: