Over the past year I've probably painted about 200-400 Germans in 28mm; and I can say I am sick of Feldgrau and Feldgrün. It's a bit of a problem when you can't stand painting the uniform colour of your army any more and you still have another fifty to paint. So why not mix it up a bit?
I'm a huge fan of having individuals in an army. I have a model of a German Unteroffizier petting a cat, and I have a bunch of unique, kitbashed soldiers mixed into my units. This idea has only been recently been implemented in my assembly, but now I try to have one out of every ten guys to be doing something different, or in a unique/interesting pose. This is to help me not get burnt out on assembling the same pose over and over.
On to painting; Like I said, I am sick of painting Field Grey. So I borrowed a book from a friend,(German Uniforms of the Third Reich 1933-1945) that displayed the various uniforms worn by the Third Reich. This book didn't just contain Wehrmacht uniforms, but various labor divisions, railroad workers, etc. It provided massive inspiration for variations on the usual Soldat. I've also created variations for my Wehrmacht forces. Some have more grey uniforms, some have more green uniforms, just to mix up the uniforms and create a more intriguing force on the table.
Are all my variations historically accurate? No. But they don't have to be. In my mind, the hobby is about being creative. So be creative. I prefer to have some what historically painted uniforms, but are my armies accurate? Hell no! But they are in typical "military colours". Just don't paint your uniforms in some silly bright colour, or do. Just make sure you're having fun!