Need help connecting a MJ Acoustics sub to Bel Canto monoblocks

I just acquired a MJ Reference I MK III subwoofer and I have a question about connecting it to my Bel Canto Ref 500 M’s. This sub connects directly to the speaker binding posts via a "speakon" cable. The speakon cable connects to the sub and then splits into red, yellow and black wires. My understanding is that the red wire connects to red output terminal on the right channel of the amp (the mono connected to the right speaker), the yellow goes to the red terminal of the left channel (mono connected to left speaker), and the black wire connects to a grounding post. If anyone could confirm that that is the correct hookup I would appreciate it.

My next question is that the amps do not have grounding posts so I’m wondering if I could connect the black ground wire to one of the chassis screws on the bottom of the amp.

Thanks