Put the following code into a method that runs after the picker is completely loaded and its components filled.

CODE:

[UIView beginAnimations:@"SetSelectionBarAlpha" context:NULL];
[UIView setAnimationDuration:0];

for (id view in self.PickerViewController.view.subviews) {
if ([view class] == NSClassFromString(@”_UIPickerViewSelectionBar”)) {
[(UIView*)view setAlpha:0];
}
}

[UIView commitAnimations];

A simpler solution would be:
1 – create a black layer in photoshop
2 – add a mask
3 – in the channels pallet past your selection bar into the alpha channel
4 – invert the colors of the selected alpha channel ( cmd + i )

Now you have a transparent colorless version of your bar. There are a few other tricks and steps you can do to tweak it to your hearts content, but I’ll leave those for you to figure out. :)

much appreciated,
Mike

If I may I wanted to add that you could also have determined which alpha Apple is using: if you take 2 points on the same horizontal line, 1 in the white area and one on the text (black color),

You get 2 equations and 2 unknowns which gives you the original color AND the alpha used by Apple.

After computation, if BlackD is the appearing black through the layer and WhiteD the appearing white, then I have :

alpha = 1 + BlackD -WhiteD

Then you can use this alpha with you formula to get exactly where Apple was ;-)

Your solution seems to be much true!

then just add the selection bar you want as an overlay?

cheers,
Hans