As far as I can recall this piece was the only of a kind I have ever seen on a LIMA catalogue (maybe it did produce other units apart from this one but I have not seen it on print anywhere else). I did not know it had a fixed roof from the picture so taking a look from www.dybas.de repository I had to make a best guess.
Reviewing old catalogues, I've found that according to 1989 & 1990 editions, this item came in light-blue color. Have you had the chance to see any of those in this color? Or could it be a printing mistake?
Another note on this rather interresting wagon. Many people think that it's a copy from a Fleischmann model. It's not. Lima took themselves a different prototype. On the following picture you see the Fleischmann model. The major difference is the differently shaped bottom line of the carbody.
Both models are correct (although, the Fleischmann runs better due to steering wheels).