Trouvé sur le forum de BGG:
If you complete one of the basic warfare actions at -1 cube, can you put another multi-cube onto it later to preform the action again or is it considered complete and locked out?
- The Red Duchy power only works with attack technologies that contain a multi-color cube as part of the cost. - No, you cannot use the technology, and then activate again with another cube. That is in the Official F.A.Q.
Donc le pouvoir rouge ne s'applique que pour reduir le cout de 1 cube multi-couleur...