Think about your question...you are asking what color the IMAGE you scanned is as it is displayed on MY monitor??? For example, my computer and monitor automatically changes colors after 9PM my time.
https://support.microsoft.com/en-us...r-night-time so the color I perceive in your images can look differently depending upon the time I view them!
So the responses you get will only answer some questions about your scanning hardware/software and our display hardware/software, but it does not really say much about your stamp.
Stamp color is an area that technology cannot address. Color detection are dependent upon the person eyesight, ambient lighting environment, and time. Even 'color guides' are not reliable a few years after being published since ink and paper chemistry change over time. And there is also zero consistently across color naming conventions. So trying to apply Pantone or catalog color nomenclature is virtually useless. What one refence calls red another might call carmine.
Stamp color study consists of a big reference collection of stamps, a trained color eye, and defined and calibrated ambient lighting conditions.
Don