You need to enable Virtual Host in the NVR settings to allow you to log in directly to each camera and then in the camera image settings you should have control of the ColorVu white light settings.
The login will be username - admin / password - set when you first installed the NVR
If you have only ever accessed via the direct monitor then you've likely never used the password that was set when the NVR was first installed so you will need to follow the password reset instructions and send the password reset file to your original seller/installer to get them to reset the password for you.
Ok, this is going to make things tricky because only authorised sellers can do the password reset for you, as you bought from eBay your only option to regain access to the browser access will be to hard reset the NVR from the direct monitor menus, set the NVR up from scratch again and make a note of the login password you set. You should then be able to log in with a browser to access the cameras directly and adjust the white light settings.
I was going to say that your other option would be to move the cameras to a separate PoE switch on your local network so that you can assign dedicated, individual IP addresses for each camera and then you can log in to them directly to adjust the camera-specific settings and you can add them to the NVR remotely using that dedicated IP address. (to do this you will need to hard reset each camera as they will have been activated with the NVRs activation password which you probably don't know)
Connecting directly to the laptop would be complicated and would require far more network configuration than the above option.