in order to push the image back into construct 2 go into the top drop down menu.
Photoshop wrote: Image>mode>index set the option forced: WEB
than save and go back to construct 2 and continue designing game. I am not sure this ruins the color space for png32 because forcing it to web might make them 8bit it has similar options to save for web but that still has png 32 I am less than familiar with the web color space :p
Let me know if there is a more elegant solution or explanation.