The color of the cable doesn't matter.
To change wireless settings:
Log into your router. I assume you know how, if not: in your browser, type the router's address (
Index of /, or 1.1, or whatever you may have set it at)
Click on the Wireless Tab. Click down in the dropdown box next to 'Wireless Network Mode' and choose 'Disabled'. Click Save at the bottom of the page, then click on Apply settings.