Java SE (Java Platform, Standard Edition)

Hello everyone. I'm trying to build a small program to help people learn a about RGB colour values, and at the same time teach myself a bit more about Java. Things have been going fine so far until I came to setting my JSlider's size. The intention is to have three JSliders with a JPanel next to each. The I need the track of the slider to be exactly 256 pixels tall (one pixel per gradient value painted into the adjacent JPanel) plus whatever extra padding and spacing the Look And Feel dictates.

I've got the height set to 256 pixels in the following code, but it makes the JSlider as a whole 256 pixels tall and so squishes the track. I've set the minor tick spacing to 2 so that if the track was actually 256 pixels tall, the ticks would alternate over each screen pixel. If you compile and run the code, you will notice that a few ticks appear next to each other without a one-pixel gap between them. I've also verified it by taking a screen capture, pasting it into the GIMP and then using the measure tool to check the size.

I've tried searching through the API documentation to find ways of doing it, or to see if some ideas I've had so far were possible, but so far, I've not found anything particulairly satisfactory. I even tried to see if I could set the JSlider size to current JSlider size minus the track size, plus 256, but I couldn't find a way of getting the current size of the track.

Can anyone help me out here? I'm rather stuck.