Red, I'd need to know the truth.
I'd take the red pill and go party all day'n'night long, score hot blue (oxymoron?) chicks. I'll probably become a sportsman too when I've proven I can run faster, kick harder, etc. etc. than others. Yup, that'd be cool. Or maybe I'm gonna try to become a superhero and save bluepills here and there. And when I get hunted by agents, I'll set the blues against the system, cause I saved their lives and the agents don't. That'd actually make me a supervillain, but the blues don't have to know that.
I would grab them both and swallow em' down just for the awsome high I would be having...
Cheers