Whooboy, if you thought the fanboy bigots frothed over Jodie Whittaker...

[Labster]

Well, the Doctor isn't human after all, or only half. It's entirely possible that along with being able to see time  a Gallifreyan's eyes pick up enough other colours beyond what we call visible light that rainbow tie-dye is a staid and subtle choice by comparison.

Or The Doctor could just have the sensibilities of a magpie, yes. There's certain;y a big enough collection of odd and shiny or blinky things littered about the TARDIS.

Or it could turn out that she's not Gallifreyan at all.  That last episode was, well...  OK, the Doctor is officially a superhero with an origin story.  And the black!Doctor was what, the Zeroth Doctor?  The Negative Second Doctor?  Way too much regeneration for one episode.

Let's meet back here in a five years and see how they retcon this one.