I'v done a quick attempt, but my computer keeps throwing up error messages when I try to edit the image in more detail..
1. This is what I meant with the 'mask' comment. The edges are to stark for a 'soft edge' camo, and the Dunkel Gelb to clean. If that makes sense?
2. The 'stippling' or spatter effect can be a few issues, as Simon mentioned, it can be to high a pressure, usually combined with too thick paint. It can also be paint drying at the tip of the needle.
You need to practice on a piece of card, or an old model. As you are doing camouflage on a 1/35 vehicle, you don't want to high a pressure, typically try 10 PSI, and keep thining the paint untill you get a smooth flow. You need very thin paint, and multiple, very thin layers, to build up the coverage. If you get 'spiderlegs' (sguigly lines running from the centre of the spot you are painting), you paint is to thin.
I tend to spary at 15psi, with my paint thinned about 2 to 3 parts thinner to paint. Sometimes even thinner, depending on how much coverage and transparency is needed.
What paints are you using, and what thinnirs?
What airbrush are you using?