Greetings Notsu! Here's the best I can come up with. My brother-in-law and I are 68 yrs old and he's Marine Vet who served in the field artillery as a forward observer. He has studied armor and artillery history for ever since I've known (at least a half century. So, I sent him the link to your post and this he told me! This is not likely to be a tanker's helmet because war wide tankers wore padded helmets because their heads were always banging into the insides of the tank.
Re the yellow camo. The soviets rushed troops out to the likely routes the Germans would take coming in. They were prepared to stay in the field for extended periods of time. There were and perhaps still are farms and vast fields that raised yellow colored crops like Mustard and Sunflowers. With the right combination of lite and dark patterns an infantryman could watch or shoot with relative safety. Perhaps this poor fellow stuck his head up one too many times and was spotted by a sniper! The hole in the brim of the helmet says a little more than "Lucky Shot". The rest of him might be lying thereabouts somewhere! Maybe you can take him home.
Best wishes!