The "63" in the docketing is proof that the date is '63.
Not possibly a 64 or 64b, since these issues were the first of the 3 cent shades, printed early, in August of '61. Very difficult, if not nearly impossible to certify a stamp as any shade of pink (64/64a/64b) with any date later than around Jan/Feb of '62.
Here are the colors identified y Mike McClung, (and you can probably find these in back issues of The Chronicle) that originated in '63:
Hope this is helpful......