Remember that discussion we had waaaaaay back about using a relay vs a smart strip?
Smart strips can allow some current through, like a dripping tap, until the master outlet draws a certain minimum then it turns on the tap fully. They have to let some current through because otherwise stuff like standby function won't work. I really don't know for certain but guess that your LED strip might use ~2-3W and falls under the threshold. The minimum to trip the circuit to fully open might be 5W.
Some might depend on your local mains power supply too. I have a smart strip in my main cab because it was the first I did and it was easy, it is still there now. That always operated perfectly in Australia. Come to rural Thailand and the power isn't regulated as well, I found the cab would sometimes suddenly try to turn itself on (starts up for a moment, 1-2 seconds, then dies) due to a surge or something. Occasionally it succeeded and I woke up to see the cab fully on! If I looked inside I often saw the LED on the audio amplifier was lit, even though everything was meant to be off, implying some current leaking through. Maybe it is developing self awareness? Cue Twilight Zone music.
Just as mysteriously, the issue seems to have gone away again. So I put that down partly to the smartstrip and partly to the local power supply management/regulation/stability. Also we put in three-phase supply a few years ago so that may have something to do with it.
Back on topic, and assuming Scott's theory about the colored outlets doesn't work out, you may get better outcomes using a powered USB hub, if it is one that stays "off" until the Pi wakes, and make sure the Pi USB ports are not set to supply standby power. Unfortunately that would mean adding another thing and cables that all need to be secured properly too.