OK no. I concead defeat.
Back in the day I did believe he had white hair. Then came Emerald and I thought it was multi-colored hair, ala Horo-horo from Shaman King. Even now, I like the idea, but nothing can prove Word of God's word (except God themselves). Well, now I can let my imagination fly and draw hypothetical hairdos for Brendan, so in the end, I'm still happy.