Whether you're going blonde, brown, or anywhere in between, there are lots of rules in the world of dye jobs. But which ones should you follow and which ones can you disregard?

We talked to Miguel Angarita, master colorist at Mizu salon in New York City, for the scoop on whether the color theories we've heard are fact or fiction.

Wait 24 hours after getting hair colored to wash your hair

Verdict: Fact

Washing too soon can cause the color to wash out a bit, so save the suds and opt for dry shampoo instead. "Washing your hair within the first 24 hours of getting your hair colored isn't recommended," says Angarita. "The color needs that time to adjust and washing it can remove some toners, glosses, or tints."

RELATED: 4 Ways to Amp Up Your Natural Hair Color

You shouldn't get your hair colored while on your period

Verdict: Fiction

This one is popular on Internet message boards, but no one seems to know where it comes from. It stems from the idea that somehow, the drop in hormones changes how your hair behaves, which may affect how it takes to being dyed. But there's no evidence of the phenomenon at all. It's "just not true," Angarita says.

Don't wear dry shampoo to the salon

Verdict: Fact.

Well, sort of.

Although dry shampoo is great for after your hair's been colored, you may have heard that wearing dry shampoo to your color appointment can prevent the color from "taking" or appropriately bonding to your hair. But this depends on the ingredients in the dry shampoo you use. "If your dry shampoo contains wax it can prevent color from penetrating the hair, so it's best to steer clear," Angarita says. How do you know if your dry shampoo is a culprit? "If it has a tint or color to it, it's more likely to block or interfere with the color process," adds Angarita. 

Red heads lose their color the quickest

Verdict: Fact

Sorry, gingers! "Red dye molecules are much bigger in size so they sit half in the hair and half out on the surface," Angarita explains, "therefore they wash out quicker than other colors."

RELATED: 11 Ways to Make Your Hair Look 10 Years Younger

Color protecting shampoos don't really do anything

Verdict: Fiction

Color protecting shampoo is your friend! "They're made without sulfates, parabens, or a lot of detergent so they help maintain the freshness of your color longer," says Angarita.

Always come to the salon with freshly washed hair

Verdict: Fiction

"The dirtier your hair is, the better," says Angarita. "The natural oils protect your scalp from irritation that can be caused by the dye."