My suggestions, for what they are worth:
Ensure that the Par 64 LED Pro is in 7-channel mode.
Assign your DMX channels to start at 1 for your LED Pro's
On your DMX Operator Pro:
Hit the "fixture 1" button.
Bring faders 1,2,3 to full up, and then in 7 channel mode, bring up fader 7 anywhere. Should be fine. ENsure your SHIFT/Channel bank button is not selected or is NOT lit.
Also, see if the LED Pro has a DMX signal indicator is lit. I always like t rule out those pesky Layer 1 issues. It should blink/flicker if DMX is being received, since DMX does send constant stream of nulls when not sending valid data).
You're using your movers, so that tells me the controller is working and you have some layer 1 connectivity(DMX cable to fixtures). I'm thinking that it's an addresssing and configuration issue on the LED Par can.
Also, just a thought, and excuse me for not reading the manual thoroughly, but I'm thinking the master fader(hehe) to the right of the Par can faders should also probably be FULL up as well. Peg that to the top and then move fixture faders 1,2,3 and 7 all the way up. Start with 7 full up, then add 1(red), then 2(green) then 3(blue) if you really want to use the Par Can fader controllers.
You sound like you have some experience and exposure, so I'm not going to assume you're some sort of dummy.
So, set the LED 64 Pros to 7-channel mode, assign them to starting address 1, then engage fixture 1 on the DMX Operator Pro. Bring up fader 7 to full, then 1,2 and 3 respectively. Bet you see something IF you see that DMX signal indicator blinking.
Let's see if we get that DMX indicator. Then try the rest one at a time. I have nearly no life at the moment and will check in often.
I don't have the DMX Operator Pro, and I won't have my LED 64 Pro's for a little bit. But, I am thinking we need to start really basic and work through it. If you lived near me, I'd send you my address and tell you to swing by and let's figure it out. So, if you're in the Sacramento area, the invite is out.