That’s true, however that was more or less a footnote and not something that featured in the published works. Hence why I said ‘canonically’, as in ‘going by the books’.
I think it would have been fine for the RoP writers to have The Stranger be a blue wizard on this basis, though.
Nope. Canonically, the blue wizards arrived around the same time as their more famous brothers, early in the Third Age.
According to https://tolkiengateway.net/wiki/Blue_Wizards the later writings retconned this, and they arrived in Middle-Earth in the 2nd age.
That’s true, however that was more or less a footnote and not something that featured in the published works. Hence why I said ‘canonically’, as in ‘going by the books’.
I think it would have been fine for the RoP writers to have The Stranger be a blue wizard on this basis, though.