Czechoslovakia Error?

I was looking through my album to see if I had a copy of this stamp



Czechoslovakia Scott #2493 issued Jan 1, 1984 in my collection.
I found this stamp in the spot where the above stamp should be



It is the proper stamp but it is missing the red color entirely!
Is this a known error? Any estimate of its value?

Thanks in advance for your help

All of the colors appear to be lightened. Possibly faded from light exposure or sunlight.

Not sure I agree with that assessment. There are subtle differences between the stamps besides the missing red.

The top thin, blue wavy line is higher up on the left corner of the first building on the bottom stamp.

The 50h is further to the right on the bottom stamp along with the group of leaves. As well the star is missing from the bottom stamp.

I can see where it could be faded, but looking a little closer it appears to me that the red and the star were omitted.

The Pofis Czech specialized catalog does not list a color missing variety for this issue. The only variety listed is for tagging.

I tend to agree with Moyock13. Close examination of the stamp does not yield any indication of the red star (or any of the red) having been printed. The lighter colors may be faded or maybe they would have had some red applied to those areas too during printing to make them darker. There is a noticeable shift between the text and the 50.

Any other ideas? Or, do you know experts in Czech stamps to share the image with?

Thanks again to all who replied

Looks like a red omission. This stamp is deserving of an expert opinion, and who knows, this may be the only used one around.

The "shift" between the text and the 50 is very common on that stamp

Where might I get an expert opinion of this stamp?