Is it possible to make the pod appearance be determined by the cargo carried?
eg Passengers get pothole theme. AO, Nomad stuff, artifacts etc get a bio warning Pod skin. Perishables get a Fragile/Persihables skin. Radioactives get a Radiation symbol and scheme. General cargo is plain.
By making the cargo determine the skin the ships will in be RP colours with no effort or need to enforce/cajole etc. Major Item in hold determines theme.