Hey there...first of all welcome, and as for your question there's no difference between these server's (they are just different servers in case people find the server over populated or a player wants to restart his journey) but the progress that you have done on one server does not apply to all the servers, you'll have to start from scratch again if you plan to jump servers and as for suggestion i would suggest you to hop on the yellow server since there was a reset recently and you could rest assured that there would not be any resets for a while there.