The model itsel is great, you did a good convertion job. Do not worry about the white, it is a pain to work. Just keep praticing. Test model (I'm thinking Space Marines troopers) are a great and somehow cheap way to hone your skills.
Well, I tried white primer, but it kind of got screwed up when I attempted to give it a black wash (I was told this is a rather simple way to blackline...)
As for the Yellow/Green, I'm still very new to the hobby (a little more than a month in,) and so I've not splurged too much on paints just yet, so... unfortunately for me (and the Farseer,) the choices of color are quite minimal =[.
Thanks for your suggestions though, I will keep those in mind when I (eventually) repaint him.
id recommend that you thin down your white or use a white basecoat so youll get a smooth and thin layer of white.more work on the gems will make him look much better and you definetly have to paint the sword in a flashy color(yellow/green mix id say) ^_^