Looks like a solid start to me, the only thing noticeably not there seems to be the heroes to lead it - take your time and find some character models for your vampires, wights, and necromancers that will look good. About the only obvious thing is that at the moment you have mostly infantry, so you will be moving slowly towards the enemy - you will need plenty of necromancy to keep them in shape to do damage when they reach the opponent!
Colour schemes... that's really up to you, but some colors are kind of "classic" so you can start there? Eg; Bone, deep Reds, dark Bronze metals, Dark Green or highlights of "glowing" Green (almost luminous colours), or Purple or Deep Blue. If you've got the army book have a look through, have a browse round this forum, or try a search on Cool Mini Or Not (try a Google search for that site) and see what others have done with their Vampire Counts - just remember, go with something
you like
I guess start with asking yourself is this a "Cold" army, or a "Hot" army. What I mean is that when choosing colours blues, purples, and other dark/deep colours will make the army feel like it's carrying a chilly feel with it, while brighter/warmer Blood Reds or luminous Greens will make it feel more aggressive and animated.
Just my two pence worth - don't forget to post pictures when you get chance - regards, 'Panda