How To Tell Whether A Stamp Is Green Or Emerald?

The title is pretty self explanatory. I'm dealing with a stamp (Either South Africa # 262 or 275) and it is printed in either emerald or green. Can anyone help clue me in on how to determine it? I'm still really new to all of this and it can be overwhelming.

The best thing is to post scans so other's can see what you've got there.


-IBFS

Ok, I'll try to unbury the scanner later! lol!

If you're like me (color blind) you'll try to figure it out but then just assume that yours is the least expensive of the two.

If the color names that you have cited are from a Stanley Gibbons catalog, these chips from their colour key might help.

Thanks! (now I just have to figure out the pesky watermarks)

Hold it next to a leprechaun. If it matches, it's emerald.

Sorry!

Go into Paint.Click on Colours/Edit Colours/Define Custom Colours.
Set the RGB to 80/200/120.
Draw a colour filled box.
That's emerald.

Thanks Bamra1! Do you happen to have any more of these numbers handy?

Choose your basic colour e.g. blue.
Google 'Shades of blue'
Choose the Wikipedia article.
There will be a list of named shades. Each has next to it a box marked Colour Coordinates. This contains several different scientific definitions of the shade.One of them is the RGB.

You need to be aware that:
a)cataloguers, particularly the early ones, were very loose about defining shades.
b)modern cataloguers are very reluctant to revise the colour definitions of their predecessors.
c)monitors are funny things.
So don't expect the 'Bamra Green' of your stamp to exactly match the 'Bamra Green' on screen.


Oh, and be careful of Googling 'Shades of grey'!

Thanks!!