Ip addresses in red indicate, I think, that the hosts are behind a firewall or are proxies. It is said that these are more difficult to download from, but I have found this not to be the case and I ignore the colour difference myself.... but I tend to go for rare files, so I will get them from anywhere I can
The best tip is to vary your search methods and terms and use which ever works best for you. Everyone will give you a slightly different suggestion and a bit of experimenting is a good idea. It is worth trying the "all types" box ... this gives more results often.
I hope this helps