Um, did you know that the current coasters have that information? The arrows are colored to match Xeno colors. All you need to do is reverse the color of the squares and the arrows. (For example, the green coaster has orange arrows, which would translate to an orange coaster with green arrows.) The only ambiguous thing is the red coaster, which has white arrows. The trouble is how to distinguish between white and clear. I guess the red coaster is for clear, and the Holiday promo black coaster is for white (though its arrows are inexplicably gray).
I took the red as being for white, and then the holiday being black/clear, which makes a little bit more sense (though not completely) ANd yes, the current coasters do have that information. Yes, you can use the current Rainbow/(Xeno) MC with either style of stash. But that doesn't mean it wouldn't be neat to have a Xeno/(Rainbow) MC set. Doesn't mean it wouldn't be more obvious/attractive for Xeno players. And, with a Xeno/(Rainbow) set you can mix and match and play up to 8 (10 with 2 "promo" coasters). Also, you can mix and match - suppose one person's favourite colour is Green, and another is Orange - you have the stashes, but you can't play both colours with MC, because the coasters as they are won't allow it. Yes, it's not imperative, it's a nice to have. But on the other hand, I can't think of any games that require having both Rainbow and Xeno stashes either. The closest I can come that requires more than 5 colours, is Volcano, as yo uneed a 6th colour of smalls for the volcano caps. But then volcano caps are available separately anyway. 1) Nice to have 2) might *increase* sales overall, if Xeno-stash preferers don't notice that MC can be played with Xeno stashes. 3) would for sure increase overall sales for those that want to play 5-8 player martian coasters (remember that the additional coaster isn't available in retail stores) Timothy