To answer Ron's Question about how we unify the models in our armies I took a look at my models and came with the following:
First long ago I decided that I wanted my orks to have red somewhere, for some it is red pants for others red shirts, to complement red I mostly use 3 main colors a shade of white, Yellow and brown as can be seen in my Big Mek
here are some other examples of unity by color pallet:
Next it is unity by style where I paint my Space Mirnes as mostly fresh of the factory while my orks are not so tidy.
The other part that I use to create unity is base style
For my Genestealers it is a metallic color and deck style for my orks it is brown and earth style while for my Ultramarines it is green base with grass style in all the bases whenever possible.
while lately I been experimenting with coding the troop type with glyphs in my orks as can be seen here:
so those are it is my thoughts on how to create unity in a sea of chaos painting to accomplish the following: