Recognition Of The Colors Of Silk Threads

Happy New Year 2015 to all of you and your relatives.

But the year is already started and we have to work, isn't it?

So, my question:
I am working on old Swiss stamps and I have difficulties in the recognition of the colors of the silk threads.
Do you know a method ( like for watermark) for revealing that color ?
From that determination dépends the classification of these stamps.
Thank you

Attached 2 scans of what I see.

These are very tricky because several of the colors listed are very close ("Emerald" and "Green", for example). About the only method I've ever used is examination with a 15X magnification (or more). Other than that, I have no better ideas!

Yes and some times red or brownred or carmin !

use the cancels on both your stamps to help identify which ones they are . {more later when I get home}

The pages at the link below helped me.
http://www.stamp-collecting-world.c...l_part1.html

Thank you.

This is for recognition of the Strubels. I have read some books on it; but based on them, it remains that only with the color of the printing and the thickness of paper, you cannot recognize exactly the stamp without knowing the color of the silk thread.
In addition, there are nuances in the colors and you cannot base the recognition only on the colors !
And, a lot of times, there are some remaining parts of paper sticked on the back and the thickness of paper is difficult to evaluate. ( I am afraid to clean the stamps in water, because I don't know if the color is water-resistant)

That's the reason I was asking if there is a physical mean to determinate the color of the thread ( of course without dammaging the stamp).
Because, if you can determinate that color, it doesn't remain any doubt about the classification of the Strubel.

According to the hereabove suggestion of Bill, I will buy a magnifier 20x and maybe I will see the color of the thread.

Maybe looking at the edge of the stamp you can see the end of the thread as a clean dot of color... I haven't done that, but maybe.

I love the discussion on the early Swiss thread colors. As you can see in this earlier thread, I was quite confused at first as to where it even was:

https://goscf.com/t/27755#237836

Even though there is a good picture of a double-thread in that link, I still think it is difficult to say whether it is green or emerald. Good luck.

@Partime
And even, without a magnifyer of minimum 20x, sometimes you cannot make the difference between red, brown and black thread.