Get the right color in iOS7 translucent navigation bar

Question

How can I get the right coloring for my translucent navigation bars in iOS 7? The navigation bar just adjusts the given color to a much brighter one. Changing brightness or

Answer 1

This works for me:

CALayer *layer = [CALayer layer];
layer.frame = CGRectMake(0, -20,navigationBar.frame.size.width,navigationBar.frame.size.height + 20);
layer.backgroundColor = [[UIColor blueColor] colorWithAlphaComponent:0.75].CGColor;
layer.zPosition = -5;
[navigationBar.layer addSublayer:layer];