During our BVI charter, SunSail supplied the ACR C-light for nighttime dinghy use:
I guess they expected someone to hold it up like a torch (that's what we did). I didn't see any dinghy in BVI with full red/green/white nav lights. Of course, that's a different country, and I cannot vouch for its compliance with international or US COLREGs. Most people seemed to just take handheld flashlights (NOT high intensity floodlights) and shine them briefly at any nearby boats as a warning that "I am here."
In St. Thomas (Red Hook) a few years ago, I noticed some dinghies that had a little post on top of the outboard with a single fixture that showed red/green/white nav lights. Having the red/green on the motor has two problems - it's not on the bow, and driver/passengers would obscure anyone's view of the lights. But it's what they did.
I look forward to other answers here for what boats do in US waters (especially the Chesapeake). I've recently configured a little raft with motor mount and trolling motor for occasional use as a dinghy in protected waters. Someday we might want to go to a restaurant and return after dark, so I'm curious over what the COLREGs are, what people actually do, and what the authorities enforce.