Allah said in the Noble Qur'an:
And among His Signs is the creation of the heavens and the earth, and the variations in your languages and your colors: verily in that are Signs for those who has knowledge.
[Chapter 30 Verse 22]
The variations in our skin colors is seen in Islam as a sign from Allah to be contemplated and admired not to be discriminated against it!
Prophet Mohammad (PBUH) said:
Verily Allah does not look to your bodies nor your looks but rather he look to your hearts and your work.
Prophet Mohammad (PBUH) said:
The white has no superiority over black nor a black has superiority over white except by piety and good action.