Spore - How to be allied with the Grox and other Empires too
Once you ally the Grox in Spore, every other Empire will instantly react with -200 diplomacy points, which will most likely make them your enemies. However, if you manage to get at least +151 points before allying the Grox, they will drop only to an orange or yellow face (be aware that diplomacy points for your alliance don't count since the alliance will be cancelled the moment you ally the Grox).
It works best with Empires who value your friendship since this can give you up to 100 additional points as seen in this video.
You can then do whatever it takes to get them back to friendly and form an alliance again. Good Luck!