Why command color disappears when I switch user?

I am current logged-in as portait through GUI login. Whenever I typed any command in terminal it is displayed in blue color but when I switch user sudo su ramuG and typed any command in terminal it becomes colorless? I am not expert in this field as I am just starting to learn linux. It is not too serious problem but it would be more easier to learn linux command line if someone could help me solving this issue?