Hi Shawn, on the Benjamin Moore paint fan, those colours are all very close. The client had the final say between the three, and because they made the selections independently we don't have the final choice. We'd recommend you have an APEX sample board made up with your acrylic colour selection prior to finalizing your pick. Kendall Charcoal is the cooler grey of the 3, and Chelsea Grey is the warmest, Iron Mountain is the darkest, you can't go wrong with any of them! Good luck.