16 million colors vs any other mode?

I have a few games I developed for iOS and Android. Now I tried changing color modes recently to see if it makes any noticeable difference in run time and tbh I could not see any change to performance on android (didn't test iOS yet). What are the advantages of a game in a lower color mode vs 16 million? Besides a lower file size. Does it help performance at all? I was not able to find a noticeable change in frame rate. (they were originally made in 32000~ colors and upgrading to 16 million did not seem to make a performance hit)

The reason I am asking is if the pros outweigh the cons I will update the graphics for 16 million. Any input would be great! thanks in advance

Thanks Danny. I feel silly as I wasted countless hours optimizing the color pallet for 32000~ colors. I just remember reading it (probably in the iOS forum when it first came out) to use it for performance but phones these days are getting more and more powerful.