Stylists are generally really careful when they are applying color but due to Murphy's law, if you come in wearing any color but black that’s expensive/precious to you and you want to get your hair colored, shits gonna get stained. If you do come in for a color, just to be on the safe side, wear some grubby clothes.  
*Side note: Don’t wear turtlenecks, bunnyhugs, cowl necks or anything else super bulky around the neck to your appointment. Your stylist won’t be able to get the cape secure around your neck, causing fresh cut hair, color and water to drip down your back, which if you're not aware, is awful and uncomfortable.
*Side side note: Also, because of my hate for them, just don’t wear turtlenecks, ever. They have the ability to make almost any situation creepy, although an impressive skill for a shirt to have, not a quality an item of clothing should possess. As a general rule of thumb, any item of clothing you buy should not look like it comes with a matching van with tinted windows and trench coat. WHICH IS WHY YOU SHOULD NEVER BUY A TURTLENECK. 
*Side side side note: I may have some personal issues that involve turtlenecks, I see that now. However due to the fact that I already have a huge pile of issues to sort out, making peace with turtlenecks isn't high on my priority list.  

 Fun fact: It’s hard to cut hair and hold a conversation with a gold mine of ear wax staring you in the face.  Generally this is a problem with older male clients. Seriously, I'm not being a "man-hater", if we did a statistical breakdown of who comes in with the waxiest, candle forming ear canals, the demographic would undoubtedly be older men. STATISTICS DON'T LIE! So if you have an older man in your life, do their stylist a favor, pin down your loved one and clean their ears out before they get their haircut.

Also, clean behind your ears. What you can’t see can often grow bacteria and horrify others. Here’s why routinely washing behind your ears is important; it’s dark and it's moist which makes for the perfect breeding ground for bacteria.  You know what this leads to?? smegma. If you don’t know what smegma is, than consider yourself blessed. It's a white, sticky film that smells of dirty belly button and feet and once you smell it, it will haunt your dreams forever.  If you notice your stylist scrubbing extra hard behind your ears during your wash, consider it as a subtle hint to get your shit together and start scrubbing your ears on the regular.

*I’m not a doctor, but i am a germaphobe with OCD who's haunted by the nightmares of other people's smegma. Therefor I am clearly the most qualified to be giving out cleanliness guidelines. 

You can check out Part One and Two of Zelda's Unspoken Salon Rules here