Yellow means the port is not blocked, but for some reason not fully open. For example, if I open a port that doesn't have a server running, I would get a yellow. Try testing directly from one computer to the other, over your local network. If you can't get in that way, you won't be able to get in from the Internet. Do your testing one step at a time, to see where the problem is. However, at the moment, it appears your problem is somewhere within your Windows 7 computer.
BTW, does your raspberry pi get an IPv6 address on your subnet? If so, you can access it directly with better methods than VNC. For example, if I want to remotely run a graphical app on linux, I use ssh with the -X flag to get to a computer and then issue the command for the app.. This then allows the app to use the graphical interface on the remote computer. To do this with Windows on the remote computer, you'd have to install something like Xming and also putty. If the remote computer was Linux, it would just work, without having to install anything else. Ssh also provides full encryption, which is something VNC doesn't support by itself.
The gogo is listed as Unidentified network, public network, no internet access, "local area connection 2"
I have found the displayed info doesn't work right on Windows. Check the gogoClient status tab to see the relevant addresses. Of course, if you can reach an IPv6 only site, as you did with the port scan, you know the IPv6 tunnel is working. You will have to check with other computers on your network to see if they also have IPv6 available. You can do this with the ipconfig (ifconfig in Linux) command or just try opening a browser to an IPv6 only site.