Are you going for the white topsides and gray undersides as was often seen on the C-141 fleet after they went through periodic fleet maintenance intervals?
I'll be trying to copy the scheme that the KC-10A wore before going to grey, which is basically as you said, white top, grey bottom. Instructions recommend Gunze H57 for the grey, can't find a conversion chart that lists an equivalent, so I may have to go with whatever looks close.
Probe and Drogue AAR Pods under the wings would be a nice feature too but I suspect that is not something provided in the kit so you will have to build from scratch or source from another kit.
'Twould be nice, but as you said, not provided. And trying to scratch some in 1/200th would be challenging to say the least!