I'd like to replicate the default color of the UITextField placeholder field. From the documentation:
The placeholder string is drawn using a 70% grey color.
This is 70% grey:
UIColor* grey70 = [UIColor colorWithWhite: 0.70 alpha:1];
It is white but only 70% of the maximum brightness (1.0).
1.0 is pure white, 0.5 is middle grey, 0.0 is black.