How to Apply a Translucent Loose Setting Powder

Hi Lindsey,
How are you? I just moved to Colorado and I'm sad I can't come see you anymore! After all, you did completely revolutionize my look by making me grow out my eyebrows!
I had a quick question for you. My friend bought me a Laura Mercier anti shine translucent matte powder. Another friend told me that using it with my Bobbi foundation will make me grey!! Is this true? I want to make sure I can still return it, so I'm afraid to try it!!
Hi Kelly,
How are you? Thank you so much for writing! So here's the deal with the Laura Mercier powder- it will look grey is you pack it on with a brush- and the brush will wipe off some of your concealer and foundation anyway- which is no good. You have to go grab the Laura Mercier Velour Powder Puff to apply it- very lightly. Shake it once and open it up- the powder in the lid is all you're gonna need. Make sure you rub the powder around on the puff before you apply. I would just apply it to your T-zone, or wherever you get the shiniest. I'm totally going to make a video of how to apply it when I get back home to NY from my vaca! I love it! I'll make it on Wednesday! :D
And thank you soooo much for writing that review of me on Google! You are soooo sweet! It's people like you that make my business so amazing!!! Without you my business would be no where near where it is today! 
And Here's the tutorial:
[vimeo w=500&h=281]
Also, Laura Mercier has this new powder, Invisible Loose Setting Powder. Nicole Wittman, a makeup artist that lives in LA and works at Laura Mercier, says that this is the new and improved photo ready powder. It's just a better version of the older, thicker translucent powder. The original powder doesn't work on Espresso skin tones on camera. Maybe this one will! I hope I can try it soon and let you know what I think! *UPDATE I think the original translucent formula is better that the new invisible formula. The new formula coagulates really strange underneath the eye on top of concealer.