The problem is in this line:
view.backgroundColor = [UIColor colorWithRed:(200.0 + i)/255.0 green:(200.0 + i)/255.0 blue:(200.0 + i)/255.0 alpha:1.0];;
Whenever Red, Green, and Blue has the same value, the color is gray.
Add constant value different then 200 to, at least, Red component and you'll see different colors.