I scanned 2 equal sized photos of mine & my brother & opened them in adobe photoshop,then zoomed out till both broke into square shaped pixels.
I noticed the total number of pixels was same in both photos but the pixels differed in their colour.
Can I change the colour of each pixel manually to change my photo into my brothers photo ?If no,why?
Color change from image to image taken by a camera for exposure lighting and camera angle change. Images taken nearly the same and close together should have close colors and exposures. You may want to explore photoshop match colors feature.
Menu Image>Adjustment>Match Color...
You can stack the images and morph between them using tutorials found on the web.