I hope you don't mind if I offer a little bit of constructive input?
It's looking good so far, but I would definately lighten up the green you have used on his head, hands and feet - Yoda was pretty pale in ESB. A great base color to start with is Tamiya XF-21 - it's an acrylic so good for this project.
After that, mix some brown acrylic with water and brush it over then head, hands and feet, then dab off the excess with a sponge or old towel. Do the same with a watered down black acrylic mix. Tiny bit of paint, lot of water. That'll weather him and bring out the detail in his features.
For the hair, best I have found is real human hair (ebay) although I have heard of Santa beards being used very effectively...really! Stick the hair on in very small sections at a time with a tiny dab of superglue.
Finally, as others have commented, get those robes weathered! Yoda was a mucky pup. Take them off and drag them round the yard, or alternatively mix some very weak tea / brown acrlic paint (a tiny amount in a lot of water!!) or mud and water in a plant spray bottle and squirt him down with that, for the authentic dagobah grime effect.
Hope this helps a little - looking forward to seeing him finished!
Regards
Al