Welcome to the forum. Some pictures would help. (And for posting pics.. Keep them smaller than 1000px on the longest side, and compressed to 200Kb, and you should be fine)
Iv'e had them potted around 3 months i think. They have been outside all winter too as i don't have room.
The 2 smaller ones have a few browned leaves, I know they are supposed to go that pale white over winter that's one of their beautiful qualities as a bonsai. And then bright green in summer.
I have dropped a little Naruko on them yesterday as all my plants are starting to grow now.
I am not entierly sure on how to deal with trees as I have only kept fruit bushes up until now