Update:
At the 4 week mark of using IP yellows 5 IU/daily, the typical HGH side effects began kicking in... fingers tingling, joints sore (elbows and wrists mostly), and increased vascularity; all of which sub-sided while on IP blue tops. For me, that short-term evidence suggests the blue tops are trash.

And the fucking crazy thing is.....

I did a long cycle of test and mast for 15 weeks, and I started my typical 3-4 week pct on 10/16, but only this time I added the yellow tops one week prior to pct on 10/10. It's now 11/27, and I haven't lost a single pound. I even continued to gain very slowly post-cycle and have added 3 pounds since 10/16.

I can't deny those facts, therefore....

Conclusion:
Blues are bogus.
Yellows are legit.