Rihanna is opening up on her decision to turn down the NFL’s invitation to perform at the Super Bowl last year … saying she “couldn’t dare do that” to Colin Kaepernick.It was widely reported that RiRi rejected the SB 54 halftime show — the biggest entertainment event in the world — because she believed the controversial NFL QB was being blackballed. In her cover story with Vogue, the singer confirmed she was taking a stand against the league. “I couldn’t dare do that. For what? Who gains from that? Not my people,” Rihanna says … “I just couldn’t be a sellout. I couldn’t be an enabler.”“There’s things within that organization that I do not agree with at all, and I was not about to go and be of service to them in any way.” At the time, Rihanna wasn’t shy about her displeasure with the shield … and she even mocked the league in a video she posted while on an airplane during the Super Bowl.