By all means, Google hetzer 38t then click on the images tab. There are plenty of color pictures, but if you want an authentic pattern, focus on the black and white pictures and what appear to be period color images.These would be primary sources and are more likely to be real operational schemes. Next, study the artists' illustrations, These are secondary sources, presumably based on real schemes. Third in quality are museum pictures and reenactment vehicles. You can tell these by the high quality of the color image...good focus with no fading. I'd consider these tertiary sources. Lastly, study other models. These are very weak sources as they are interpretations of one of the first three types of sources and should be taken with the proverbial grain of salt. Some might be dead on accurate, but others could be quite fanciful.
You'll note as you look at these, some had soft edged camo and others hard edged. For the hard edges, cutting low tack masking tape to shape will work on this vehicle since it has nice flat surfaces. If you choose a soft edged pattern, you should be able to replicate this with your air brush. Quite frankly, that's a skill all modelers should develop. Low pressure, thin paint and keeping your tip close to the surface and either perpendicular to the surface of aimed into where the pattern is filled with the color you're using.
As mentioned, the colors were a base of dunklegelb (dark yellow) with rotbrun (red brown) and dunklegrun (dark green) as disruptive patterns. In the ambush pattern, the colors have spots of contrasting spots to replicate the mottling effect of sunlight through foliage. Some of these spots were roundish and others in hard edged angular shapes.
Yes, it's yours and you can ultimately do what you want,but I'm assuming you asked for advice so there it is.