How are Africans treated in Saudi Arabia?

How are Africans treated in Saudi Arabia?
Living in Saudi Arabia for 2 years and I have seen no discrimination on color basis at all. There is lots of black Saudis, Africans, Sudanese, Senegalese, Indians, Pakistanis, Egyptians and Saudis are accustomed to that and are nice with them .

The anguish may stem from the fact that Saudis feel those outsiders take our jobs and our money while we have 12% unemployment.

It depends on a few factors:

your skin color. if you are dark skinned chances are you will face a lot of racism
your religion: if you are muslim, there will be less prejudice towards you. however, if you are white and christian, you will be alright, and if you are black and muslim also you should be alright. Problem is if you are black and christian and african.
work you do: if it is a well respected job like doctor, engineer etc you will get more respect.
your nationality: there is a pecking order in saudi and it is there for all nationalities. It goes something like this:
top tier: all whites (american, uk, european union and south africa) and saudi citizens, citizens of uae, bahrain
all non-whites of the above mentioned countries
all muslims from countries like egypt, libya, yemen etc
all muslims from india/pak
all other religions from india/pak
all people from asian countries like phillippines, malaysia, indonesia, etc.