Glass tile installation?

I have selected 2 inch frosted glass tile for the backsplash behind the cooktop and I have hired a professional installer. I have two issues. One is that he says the grout lines are small and the job does not need to be sealed because it will make the grout darker. And two…when he cut the tile for the sides and corners, the color came off the back and he is telling me I need to have a moulding installed to hide these pieces that have lost their color.. He says all glass tile loses it’s color when cut into small pieces. What’s up? Should I go back to the manufacturerregarding the color loss, and should I insist that it be sealed to protect against grease and splashes.