Yes, it appears the folks that build the underlying PlantUML code decided that the default colors should change. They are not changing randomly, but only once with the latest version of the code. It appears they want the default to be this sort of neutral color and want you to use themes now to get the look you want. You can read more about this here … https://plantuml.com/theme. Just add “!theme spacelab” or “!theme amiga” as the first line in your PlantUml. I hope this helps. I will add a popup “News” screen on PlantText to let people know what is going on and the best way to get the look they want. Cheers.