Proper way to use images in NSMenuItem?

Question

I've put some images next to NSMenuItems using the image option in Interface Builder. The custom image is a simple PNG. I was hoping the system would automatically alter the color of the image during mouse over like it does with stock images. It does not. What am i doing wrong?

Here's a pic of a stock image vs my custom one:

Answer 1

In code, call [menuItem.offStateImage setTemplate:YES]