You can still do this? That is just great. I had reported this way back in Jan 2017 through support. It was about upgrading your ships with a colony module and being able to colonize with 0 pop. Both would be fixed if zero would deny colonization.
Normally minimal population limit denies this. But I found an exploit in that upgrading a ship to a colony ship still allows it to colonize planets even though it has 0 population on board.
Also such a colony would be useless if the population growth took into account the current population like in GalCiv 2. But sadly the colony ship crew are able to get 300 million people for the planet in a week as seen in the screenshot.
I have forwarded your report to our Development Team for their review and recommendations.