Imagining Django to feel great solidarity with people based on skin color is anachronistic, not in keeping with the character, not in alignment with his primary motive nor his mentor's identity, and frankly racist. Just because strangers have similar color skin doesn't make them your family or friends. It was a tough world. Django knew he couldn't really do much about something as vast as slavery, but he couldn't live without trying to rescue his wife.

In actual history there is the inspiring story of John Brown and his attempt to free many slaves and start an uprising. For those unfamiliar with his story please read up on him. Historians say that his efforts though a tragic failure at the time helped insure that the Civil War and freedom would come sooner than later.