I have extremely fair (NC10-15) skin, and picked up a full size "refill" pan of this locally on major sale for just under $3 in the shade "20 Watts". The shade looked like a good match for my skin ton...

This is my HG concealer. It matches my very fair skin tone beautifully (I use the lightest shade) and blends well--as long as I use a primer underneath (my favorite is Smashbox's original clear primer...