This has nothing to do with the ethnic background of the person. The whole thing comes down to the passport that you carry.
If you carry a Western passport, especially a British, US, Canadian, or Australian passport, then you will receive a (much) higher salary (sometimes up to 3 times that of your non-western peers) and many perks.
So, let's say that you are a construction project manager with non western citizenship: you can make around $40k/year for that job. But if you do have a Canadian citizenship, for example, you can earn up to $120k/year.
The logic behind this may be that the cost of living is substantially higher in western countries than in non-western countries.