Please note that, if i thought you needed gushing praise this piece earns it in full amount, but my understanding is that you value critique more than anything, and im sure a piece as good as this will earn more than enough praise to float any man's ego. so with that being said, here's my critique.
Helm, you have a wonderful sense of color that in my opinion is not demonstrated in this particular piece. perhaps you could explain why you chose the hues you did? Keeping your goal in mind, they appear entirely arbitrary, almost counter to that idea, and that leads me to feel as though you were trying to force a different relationship between the colors that simply does not exist. the combination serves to provide the portrait with a complete lack of life. Also, in every picture i have seen of Tesla, there is a quality that exists in his eyes that this portrait does not capture. Though the man in the picture looks like tesla, he also looks dead, inside and out, and that is something that i simply dont associate with a man like Tesla. my suggestion is to perhaps change the colors of the face not only to be warmer and more alive but to have a better relationship with the other colors, but most importantly though i think something in the eyes need to change, personally i think he should be looking at the viewer, as at the moment he is looking away and down as though he has been in some way defeated. If this was your aim i applaud you, but from looking at this piece i do not feel that it is 'EXPRESSING THE AWESOMITY OF TESLA SCIENCE.' Pieces that are technically brilliant can still fail in their goal, and i dont wish that for anyone, especially not someone with your talent and a piece executed with this level of skill.
good luck, its an awsome piece you have here, especially for the timeframe