I modified the ATT Animation and inverted all the colors so it's on a black background. It looks a lot better than the stock one imo. Assuming your ATT_bootanimation is located in system/customize/resource/ATT_bootanimation.zip, you can flash the zip in recovery. I also included the original in case you want to go back to stock. Note I've only tried this on a Vivid with wcx rom, not liable if it doesn't work.
Huge thanks to homeslice976 for helping me figure out how to get it working and the flashable zip file.
Good job! Looks sharp!!