CSA #11 and CSA #12 Color Shades

The CSA #11 and CSA #12 stamps exist in a variety of color shades from a deep Cobalt Blue to various shades of Blue and Greenish-Blue and even in a true Green color. These color shades can be very confusing to the average collector and can be difficult to distinguish especially when the stamps stand alone.

Here are a few basic rules when it comes to the color shades.

Any CSA #11 or #12 stamp with a greenish tinge or a true green color is an Archer & Daly printing. The Keatinge and Ball printings do not exist with a greenish color.
The deep cobalt blue exists only as a Keatinge and Ball Printing.
The Greenish-Blue color shade is fairly common while the true Green color shade is actually quite rare.
It is much easier to distinguish the color shades when the stamps are viewed side by side.

There are seven acknowledged main color shades

Cobalt Blue -- Dark Blue -- Blue -- Light Blue -- Milky Blue -- Greenish-Blue -- Green

In order to better tell the difference between the color shades, I have put together seven stamps which are the best examples I could find of these color shades which I use as my own reference copies. Having reference copies of these color shades particularly if you intend to collect CSA stamps in detail is a good idea. Below are the scans of my color shade reference copies. I have done my best to scan with true colors, but the shades may differ a bit depending on your own monitor settings. But this at least gives you an idea of how different and subtle these color shades really are.


Cobalt Blue	Dark Blue	Blue	Light Blue


Milky Blue	Greenish Blue	Green