Bukkit

/nbt toggle pet sitting To be used on dogs and cats (tamed and untamed) /nbt toggle wolf anger to be used on untamed wolves (untamed) /nbt set cat type CAT_TYPE to change a cats type (tamed and untamed) /nbt set wolf collar color (Commented out but there for those who want to build the source themselves, it does have some issues though)

 /nbt set wolf collar color r g b [Wont work but structure exists within code]
Won't work, but you are free to work on it, and if you get it working please submit a pull request to get it implemented