Do the hadiths that describe black people as slaves mean that human slavery is associated with black color, or are these human standards based on color discrimination?

There is no connection between blackness and servitude, for a servant may be white and a free person may be black. The prophetic traditions described some servants as black, but this does not mean that blackness is a cause for servitude. The basis for legitimate servitude is disbelief, not blackness. The diversity of colors is one of Allah's signs. Superiority among people is only by piety, as stated in the verse: "Indeed, the most noble of you in the sight of Allah is the most righteous of you." The Companions and the Successors affirmed this principle, favoring those with piety even if they were servants or black.