my shower is floor to ceiling grey porcelanosa with grey grout to match. the color is starting to turn cloudy due to soap. any advice on what products can safely be used without discoloring the tile color

That is a good question, you don't want to do anything that could damage the tile or grout and void any warrantees.
My advise would be for you to contact both your tile installer and Porcelanosa. Your installer will know what type of grout was used and how to care for it. Porcelanosa manufactured the tile so they would know exactly how to clean it.
Good Luck!