by DocCool
Your post from yesterday didn't get deleted, it got moved to here: https://videogamegeek.com/thread/1975183/digidiced-playing-a...It's quite unfortunate that the admins do this without leaving at least a ghost link.
You received some replies over there. This thread however likely won't get moved as it's a rule question and not an app question.
Regarding your question: unlocking the home color of another player requires a priest plus two coins, other colors cost a priest plus one coin. The coins must be leftover from the previous round; income from the current round cannot be used, nor can you do direct XYZ-to-coin conversions to get these coins. I.e. you have to take care BEFORE YOU PASS that you have enough coins for terrain unlocking when the priests arrive.
If you have the coins then you can unlock as many colors as you get priests - there's no limit.
You find the official rule changes for the Riverwalkers (and the Shapeshifters) in the thread pinned to the top of this Rules forum.