Italian Classic Stamps - No Colour Varieties?

I don't have a specialised catalogue for Italy, but from what I've been able to learn online, it seems there are no recognised colour varieties, at least for the classic stamps - which are the kind I'm sorting through at the moment.

The following scans show an obvious difference between the appearance of two stamps of the same issue. Should I assume that the more intensely coloured examples are not colour varieties at all, just overinked stamps?

What do people think?

What do they look like on the back? Could they be considered wet/dry printings?

I haven't heard anything about that subject before, Rileysan. How would I be able to tell? What would I be looking for on the back?

Look to see if the image of the stamp is visible on the back. A wet printing tends to be darker and not as crisp as a dry printing on the front, and has a tendancy to soak through the paper. The other extreme is when a dry printing leaves the image looking faded or even incomplete.

It's a part of the human element in using a printing press ... mix the ink too dry (or forget to add ink to the easle) and you get faded or incomplete images. Mix the ink too wet and the ink can run or soak through the paper. It's truly the job of an artist!