Group XP Bonus?

[Zheta]

Is there a group XP bonus on Blue (i.e. bonus XP added for each additional member)? I thought that system was only active on Red. Multiple guild members seem to think a bonus exists on Blue, but I've heard and read conflicting things. I've only ever seen XP slow down with additional members (barring missing a a crucial group role) with safety, community, and such going up as the benefit.