Wehrmacht / Lagergeld 2 Reichsmark (in English)

Hi all,
First - my apologies writing in English. In case moderator deems it appropriate, please do move this to "foreign" part of the forum.

My question concerns Wehrmacht 2 Reichsmark Lagergeld notes. First some background: I've known that there should be two varieties, Rosenberg 519a with blue paper and Rosenberg 519b with white paper. I bought two of these notes over 10 years ago and have always considered that I have both 519a and 519b in my collection.

Recently, I though my 519b or 'white note' is in a bit rough shape and though I should buy a new one. I bought a new one, accidentally getting a 519a 'blue note' - this was my error, and resolved with seller (this is still underway).

Now to the actual question(s): left and right notes are the ones I bought 10 years ago. Left one being clear blue and right one I've assumed to be discolored/dirty grayish-white. The recent one, however, seems to be somewhere in the middle colorwise, in my eyes it seems to carry a bit more greenish hue ... surely it is not as blue, as my old one, but not as white/gray as my other note. All three notes carry the correct 'blumenkreuz' (not sure if that's the correct word, excuse me if it totally wrong) watermark.

- what is the value of genuine white/greyish-white 2RM note. I've now heard that it might be fairly valuable?
- are there more than one variety of the blue color?
- basically, what is going on? :)

Best regards,