Donald Trump's inexplicable rise from racist real estate mogul to xenophobic GOP frontrunner has been marked with many oddities, including his unnatural orange hue.

The source of Trump's radioactive glow has largely been kept a secret, but that doesn't stop voters — and other politicians — from speculating. At a rally in Atlanta, fellow presidential hopeful Marco Rubio said Donald Trump has "the worst spray tan in America."

"Donald Trump likes to sue people," Rubio, a human adult, told the crowd. "He should sue whoever did that to his face."

Just how does Donald get this look? It could be, as Rubio suggests, a spray tan. It could be from a tanning bed, which would explain the noticeably paler skin surrounding his eyes (from wearing those little goggles). But for all we know, Trump could just be Scrooge McDucking himself into a giant vat of Nacho Cheese Doritos.

Donald Trump won seven states on Super Tuesday, so one thing's clear: the #TrumpTrain is not slowing down any time soon. That's a scary prospect, considering some have suggested that he's likely to win the Republican nomination.

I just can't let this happen. 

That's why I launched a full-scale investigation into the source of Donald Trump's fake ass tan: so that we can stop being distracted by his cheeze-doodle aesthetic and focus more on the dangerous garbage spewing from his mouth.

I started by combing through thousands of pictures on Getty Images where I found that Donald hasn't always looked like a grumpy pumpkin. In fact, there was a time when Trump almost resembled a human.

Donald Trump with his ex wife, Ivana, in 1982.

photo: Getty Images

By 1999, it seems like he might have started to dabble in sunless tanning.

Trump at a news conference in 1999.

photo: Getty Images

But by 2005, his innocuous dabbling seems to have turned into a full-blown addiction.

Trump at a Fashion Week after party in 2005.

photo: Getty Images

Most noticeably, he's really amped up the orange during his presidential run.

Campaigning in February 2016.

photo: Getty Images

After some extensive Googling, I stumbled upon the IMDB page for "The Apprentice," where I found the name of someone who seemed to do his makeup — Sharon Sinclair. I figured she'd know a bit about his beauty rituals, namely if he used a drug store self-tanner or just layered himself in bronzer.

Sharon Sinclair did not immediately respond to Revelist's request for comment.

I went directly to the source himself, who obviously did not respond either:

Thankfully, I got in touch with professinal makeup artist Lorelei Vivienne, who weighed in on what — and why — Donald's using what he's using.

“I think he’s layering on the self-tanner to achieve the look of bigger eyes, which he’s totally achieving here," Vivienne said.

She added that if anyone wants to "get the look," they can check out this Ben Nye orange face paint for just $3.50! Affordable and long-lasting coverage.

So while the origin of Trump's fake ass tan remains somewhat of a mystery, there are a few things he can do to make himself appear almost human again.

"We know you're a pale man," Revelist's Senior Beauty Editor, Alle Connell, said. "Please match the bags under your eyes to the color of your face."

"Also, fill in your brows, girl. Fill them in with your tiny little shrimp fingers," she added.