http://www.cbc.ca/news/canada/canada...glow-1.2955566
http://www.cbc.ca/radio/rewind/the-g...bate-1.2950696
It was very nearly a red white and blue flag with three leaves and a branch.
Coin people will probably recognize the pre-leaf red ensign flag for the design is the same on the circulation gold $5 and $10 coins of 1912 to 1914. Which never made it to western Canada before the war broke out, and were subsequently - revoked from circulation before they even really saw much use.
PS: I'm pretty sure the black and white photo in 1964 of Pearson shaking hands with the "winner" is standing in front of a red white and blue version of the flag. Its still pretty hard to comprehend that colour photography was still in its infancy at the time.