need help

Add a bit of light gray, white or buff/light tan to it,if you are airbrushing it on. A few drops will do. If you do a base coatof basic OD, and apply the lighter coat on horizontal upper surfaces such as the turret top, engine deck etc. in a lighter manner like a "tint" it will have lightening/fading effect with a bit of practice.

I would avoid white. I did this on a B-17 last year and it looked bloody awful. I ended up repainting the whole thing and second time around used buff to lighten the OD. Worked a treat.

You can also fade with oil paint dots,the way The Doog and Wbill76 do.It involves using dots of different color oil paints and mixing them on the model with a thinner dampened brush.Its pretty effective,for a more detailed explanation,just search for"oil dot method"

Here'ya go..........

  OMD, the link actually works