The Retribution expansion added a one-per-player colonization center that provides some bonuses when it is built. Its costs include one food, which seems reasonable for races that use food. Silicon-based races don't use food, but their colonization center also requires food to build. Some players have complained that this is wrong.
This mod replaces the need for one food with a need for one promethion for silicon-based races to build the colonization center. This matches their need for promethion to build cities.
This doesn't help much if a source of promethion cannot be found quickly enough. To remedy this, the mod includes a factory that slowly makes promethion. It is available at the same time regular factories are available. To make sure the factory isn't too powerful, it costs more to build, costs more to maintain, doesn't give any adjacency bonuses and is one-per-race. If it is no longer useful, it can be destroyed.
A zip file of the mod is available here.