In my experience, an item is sold for one of two reasons. They can serve a need or be a luxury. To me, ship skins seem to be neither. The colours you can get don’t stand out on their own over others to be considered a luxury. And its obvious that painting your ship serves no need.
My suggestion is to give the skins some heart and meaning. There is the option of them serving an emotional need if buying the skin unlocked the content to go and get that skin. Instead of buying the skin, you would buy an experience with the skin as a reward.
Some might be hard. Some might be easy. But you would wear those colours for a reason. By providing an emotional need, it fulfills one of the two criteria. Emotional needs are also easier to sell in general as well which to me gives more weight to the idea.
Example: Instead of selling it as a ‘skin item’, sell it as an executive invitation to a dinner with the ceo. The skin just says you did the thing that makes you a part of the club of people who did the thing.