You are in front of Darth Vader, Number 2 of Palpatine's Galactic Empire...
It is obvious that you are an imperial officer.
But...Your skin is blue, your eyes are red, your hair are black...You are taller than most of humans beings.
Vader says to you : "Well Colonel Thrawn ...Although, you are not a human, it seems to be that the Emperor is very pleased with your progress...And so do I. That's why we decided to promote you to the rank of Admiral. Good...Now you can break up, admiral Thrawn..."
Thrawn is getting up and says : Thank you, Lord Vader..."