Wow, your camera really did a number on the color if you say that it is more of a dark liver red color. On my computer screen it looks definitely purple and one that I would love to have if the color was true in your picture. This only goes to show how difficult it is to identify an unknown clematis from color alone especially when you are comparing it to another picture where the color may be off as well. Based on your physical description of the color and my interpretation of it, you could have Warsaw Nike, Niobe, Westerplatte, or a myriad of other clematis with similar color.