How were the minorities in Burma/Myanmar (Kachin, Karen, Rakhine, Shan, Rohingya, etc...) impacted by British rule?

For Kachin, they were almost completely converted to Christianity. Before being converted to Christianity, they were Animist. And for Karen, they were partially christianized. Nowadays, around 20% of Karen believe in Christianity and the 78% believes in Buddhism and the remaining 2% believe in animism.