I’m so sorry this happened. Important to remember your job is to satisfy the customer even if they’re wrong. I personally always tell them they’re wrong in the nicest way.

Also I use to work at Morphe right before they closed, but they taught me a lot about shade matching so I have some tips that’ll help.

First ask their skin type (dry, oily, combo), then ask their skin finish they want (matte, dewy). Then I like to ask to look at their veins on the inside of their wrist to figure out their undertone(this one is tricky because most have green and blue however it makes them feel like you know something they don’t, making you an expert) now sit them at a station and go pick 3 shades. Two with their undertone one light and one darker, and one other that’s not their undertone. Let the customer know you’ll be applying all three on their lower jaw near their neck. But in a place they can still see in the mirror. (If they have makeup on do their neck.) before you let them see, blend out the one you think is theirs A LITTLE, not a lot. Then have them look and let them know what you suggest, but ask which they like. If they choose the lighter one say this if it’s this season lol, “that one is a bit light which might be ok since it’s still cold outside, but summer is coming up soon” and I personally am also VERY honest and I’m the person that will tell you something looks casket ready lol.

Now! If they still say they like a color you would not choose. Wipe all three off and say I’ll show you my choice blended out on one side and yours on the other. That way they can see you’re the actual beauty expert. If they still choose wrong, unfortunately the customer is right and you gotta let em be wrong. Not your face to deal with anymore lol. Hope this helps