If you're paying $99, a different badge for bragging rights don't seem like much to ask for.
It's just a reskin with some backend extra work so not so much to ask for. But should the badge be bragging rights? Do we need bragging rights? Naming a star is not enough? Saving some bucks on all GalCivIII's products is not enough? Being able to have a say during alpha is not enough? Right now, if you preordered, you are a Founder. It doesn't matter which preorder you did, you are a Founder. Different "colours" is more like "First Class Founder" and "Second Class Founder". It may be overthinking it but humans are humans and I prefer that right now all Founders are equal (with different preordering rights) to Stardock.
I do admit that the badges are some form of indirect PR. People that comes here for first time and don't really know about the Founder program, can get curious about it and maybe take part. But hopefully, no one preorders in order to get a forum badge (only).