Change web address

Hi,

This may be a simple question, but I’m not the best at this stuff. Right now, I have upgraded to a premium plan so that I can use my own web address without the “wordpress” title in front of it. I would like to change that address. Is it possible?

EXAMPLE: Right now it is http://www.RED.com and I want it to be http://www.BLUE.com but lead readers to the same place.

Thanks in advance for any help!