The only difference between the Black and Blackout models of our cases is the color of the accents on the inside of the case.
For example, the Define R6 Black TG (first image) has white accents on the fan blades, PCI slot covers, and HDD/SSD trays. Whereas on the Define R6 Blackout TG (second image) the fan blades, PCI slot covers, and HDD/SSD trays are black.
The only other thing that is different between these two particular models is the color of the power/HDD LED's. In the Black model there are blue LED's and the Blackout model there are white LED's.