Can I play on both servers?

[False]

Not sure if it's a stupid question but I play on red99 but since it's down I wanted to roll a char on the blue server in the meantime...is that perfectly ok to do by just logging into the blue server? Basically I'm concerned that things from the blue server will patch and basically I won't be able to play on the red server anymore...not sure if that could happen. In other words do I have to make separate folders or do anything or can I just login to the blue server and log into the red server with no problems or any extra things that I may need to do. Thanks.