Ok, I'll bite.
a) It's pretty hard for someone to strike out 31% of the time and keep producing like he's been producing, for the long term.
His HR/FB seems perhaps a bit unsustainably high, judging from his own career mean (17.6% right now vs. 12.1% career, and 13.2% last year in Toronto). Now, if Colby has indeed figured a little something out, this HR/FB% figure could totally be true talent legit.... it's just a little early to say so.
c) His BABIP seems a little bit lucky right now, judging from his batted ball profile and his career mean BABIP. Insert nearly identical second sentence as in here.
d) He's done this before in Blue (good looking partial season). 2012 Colby had a 120 wRC+ in the first half, and a 38! wRC+ in the second half. That's .259/.328 with 17 HR vs. .176/.238 with a measly 6 round trippers. Right now he's .261/.324 with 16 HR, remarkably similar to his first half last year.
Disclaimer: I really like Colby, as a player and as a person. I think he's a good CF and I think he's an aesthetically pleasing entity in this particular spectator sport. But people are completely justified in withholding their praise. Let's wait and see what Gump brings in the 2nd half