I don't find the FF costumes boring because there's only four of them and their powers make each of them look very unique in the field.
The X-Men don't always have to be in uniform, but to me that has to be the starting point. They're not typical superheroes, but that's what they'll be if they just come out the gate looking like that. It won't make sense if they're supposed to be this feared and ostracized community and they just come out fighting a big bad looking just like the Avengers.
I feel you though. Bryan Singer took it overboard and it even got worse as it progressed. He had one of the worst costume designers in the history of cinema (damn you, Louise Mingenbach!) that made EVERYTHING look boring and dull. So I definitely want the reboot to be as creative as possible. No black leather/rubber, PLEASE!!
I think if they pick a mix of characters that have cool looks and powers, they could really come up with something good. These weren't my absolute favorite designs, but if you're looking for color and individuality, I always really appreciated Jaime McKelvie's approach for X-men: Blue:
x-men-blue-costumes-214258-1280x0.jpg
He made an interconnected theme with all the uniforms and gave each some individual flair. Would something like this be a good start?