I want to change PS1 prompt like this.
username@hostname 'current working directory'
$

I did the following and \n is not understood by shell
export PS1='$USER_NAME@$HOSTNAME $PWD\n$'

Is there a escape sequence for new line?

I also would like to set green color for $USER_NAME@$HOSTNAME and yellow color '$PWD'. 

What is the escape sequence that shell understands for color and new line? 

Help appreciated.

Thanks and Regards,
Dharmaraj G