The original CSX light blueish grey paint job was so hard to see it became known as the 'stealth' scheme - the locos sneak up unseen at places like grade crossings. This is not good, so CSX remedied the situation by overpainting the noses yellow, giving the Yellow Nose schemes. The first YN scheme was just over the light blue, YN2 added the dark blue flash and YN3 is a cheaper-to-apply and easier-to-maintain dark blue 'dip-job', still with the hi-vis Yellow Nose.
There are about 20 steps more in the evolution of the CSX loco paint job, but that's the high points in a nutshell...
thanks ns37 and ive notice the es44AH does not use ge trucks it uses emd truck. one more thing ns37 what happened to your chessie system csx heritage unit (es44)? cause i was going to buy it but it wasnt there