We can't keep up with The Bachelor's Sam Frost's hair transformation.

Images: Instagram (@fro01).

Forget Keeping Up With the Kardashians — we reckon keeping up with Sam Frost’s hair colour warrants its own reality show.

Back in February, the winner of last year’s season of The Bachelor dyed her trademark blonde hair a light brown, sharing the look on Instagram. So far, so straightforward.

But then, her locks appeared to have lost their brown colour, becoming more of a blonde balayaged situation (see above picture).

RELATED: Sam Frost is a blonde bachelorette no more.

However, in what feels like a plot twist from Groundhog Day, Sam has now debuted even darker brown hair on social media. Yesterday she posted this photo on Instagram, writing, “My hair is all chocolate brown. It’s so healthy & shiny!! Thank you once again to the babes at @salon_twosixsix you guys rock”.

First things first: it looks excellent. So sleek! But we have a couple of questions, namely: wasn't Sam's hair already on the browner side of things? What's going on here?

A bit of investigation — some would say 'Instagram stalking' — on our part revealed that Sam's hair has changed quite a bit since she first went brown (what do you mean we should find a better use for our time?). It seems she's progressively lightened her ends, to the point where her hair was mostly blonde again, before clutching for the brown dye once more.

RELATED: Cara Delevingne says bye-bye to her blonde hair.

Unless our eyes deceive us? Make you own mind up — here's all the evidence you need, in date order. (post continues after gallery)

So what do you think? Has it actually been blonde-brown balayage this whole time and we were just thrown off the scent by subtle lighting differences? Or has Sam been gradually upping her ratio of blonde?

RELATED: Kim Kardashian’s hair just got even blonder – and this pop star inspired it.

Either way, this is some great hair. Go Sam.

UPDATE: Since this post went up, Sam has swooped in superhero-style to answer our queries and put our confusion to bed. "Ha! I did dye it brown a month or so ago, but the blonde naturally kept creeping it's way back. So now I've gone darker," she tweeted. Yep, blonde has a tendency to be a little stubborn...

Speaking of great hair on celebrities, check out all the best cuts and colours we've observed among the rich and famous lately.