Smoke out of exhaust at high RPM's....

Hey whats up guys, some may have been following my recent issues that i've had. Well my next one is light smoke out of the exhaust if i run up the gear to 4,000+rpms and get out of the gas and let the motor slow the car back down. It doesnt smoke when im accelerating, just when the Throttle body closes. The car goes rich(atleast right now while im tuning) could a lot of extra fuel be the cause? Its not black(which would be oil right?) and its not a strong white color(coolant right?) but then again, its not heavy enough to see it clearly.....

Anyway, let me know what cha think!

Did some searching and found this as what each color of smoke corresponds to....

Black smoke is gas.
Blueish grey is oil.
White is water.

I can see it in my mirrors enough....