Custom Spawning

Any object, such as structures, plants, or mobs, should have a dimension or biome restriction option. I'm making a mod with dragons in different dimensions but I have to make sure they only spawn in their dimension. this would help with that also for using custom colors for the dimensions air water and grass should be either or not all or nothing. I made a scorched landscape, but i tried using the grass path blocks but it crashed my computer, so I had to use dirt and that worked great, but I would like a more dead grass or burnt grass look without the hazy sky colors