New colony types

I have created a few colony types myself for personal use, but it would be interesting to find a way to get the AI to use them also.

Standard Colony, well balanced, not specialized in any single thing.
I also use it when I am undecided of what to do with a new colony.
Similar to your System Leader, as I usually put at least one space yard and resupply depot on them, and also space ports if I am not using the one ability that eliminates the need for space ports.

Resource Production Colony, for planets with good resources all around, good for optomized use of monolity faciliies or a planet in a binary/trinary system and with plenty of solar generators. Also have some extra resource storage.
It would be interesting to see how the AI might handle such a world type, having well rounded resource production instead of mainly focusing on a single type.

Storage World, same as your second one, used for mainly resource/cargo storage facilities.

Fortress World, better suited for good planets of medium size or larger, with space yard, space port, one or more resupply depots, and plenty of storage. Then cram full with plenty of troops and weapon platforms, and also some fighters, drones, and satellites. Handy for staging points, or simply making it really hard for enemies to easily secure a key system.
Something like this could at least make the computer controlled empires a bit more of a challenge, at least as far as eliminating them or otherwise trying to kick them out of key star systems.

Ring World/Sphere World Colony.
Same as Standard Colony, but much larger, although at that space means a Ring World alone could still compare to one each of stock colony type medium planets, while a Sphere World could compare to having several huge planets with each specialized in one of the stock colony types.

I have wondered how an the SE V AI would handle getting their hands on a Ring/Sphere World somehow (likely via capturing one).

Your System Leader colony type looks interesting, although I am unsure of the name. Perhaps something like System Capital might be a better name?
Although I think more than one planet in a each system should be packing a space port (if needed) and resupply depot, if possible, to avoid 'keeping all your eggs in one basket', as an old saying goes.

Now all we need to do is wait for someone to come along and mention 'how' to get the AI to use new colony types.