Gilles, I bought a whole bunch of those stamps
when they came out and still have matched Imprint
corner blocks.
There is basically no colour difference in any of them.
Yours look like field stock which were without the Imprints,
maybe there where different print runs causing colour
variations.
The only thing interesting for the Kane issue is ofcourse the well
known "stroke on tepee" variety which I bet every Canadian stamp collector has copies of.
