I also just purchased an M4 and the receiver has a hue of blue. I didnt unpackage it right away and seeing these posts worried me a bit. Finally unpackaged this morning and mine is a shade of navy as well. Mine looks less blue then yours [not to rub it in] but could be my lighting conditions. Its a bit disappointing cause like you I purchased the all black for the look. Maybe thats childish but you want what you paid for. Im going to let the look simmer for a bit before I make any changes or put it together.