To create a colony in a land from the Hidden Sesame series, you need to complete both parts of the story.

When you're done with the first one, click the Magic Lamp and click Restart. This will reset the land. Replay the land making different choices and finish the second part of the story.

If you do that and also meet some special conditions (clear 35% of the land, empty the storage), you'll be able to make a colony.