Not knowing which Playmobil trees & what you have in mind for recoloring them, let me give you an example for a temporary project I would use for the set 7889 tree. I would get some children's washable glue that can be removed with soap & hot tap water from children's clothes if it's spilled on them. I would pour it into a bowl, & use a wide small painters brush to apply it to the 30023900 foliage bunches one at a time. When the entire leaf assembly is coated even underneath if you desire, you would sprinkle the desired color mediums onto the bunches while the glue is wet until they are covered, & alternating colors as you wish. If you make a mistake, you can wash the assembly with hot soapy water, & start over. Once you are finished with your story you can leave it permanent or wash all of the evidence away. A similar temporary project can be done for a winter snow scene is to set up your entire scene as you want it, then take bags of loose fine grain crafting snow and pour it into a vegtable strainer. Shake the strainer containing the hobby snow over the entire scene. The Playmobil genuine pinetrees look really good done in this fashion! It will look just like real snow! There are some cautions though, do this project away from animals, & children in an enclosed room, because it will get tracked throughout your house! When you are finished with your winter scene, cleanup of the snow scene can be done using a small shop vacuum with a particle filter. You will empty the shop vac when it becomes full into large zip lock bags so you can recycle the snow for next time.