When using 'Syntax Coloring', sometimes is tricky (for me at least) to find the item in the 'Element' list that corresponds to that purple stuff that needs to be green
anyway, here's my suggestions to make the dialog a little easier to use:
1) make it so that when you click in the 'Preview' window it selects the corresponding item in the 'Element' list.
2) when scrolling up/down in the 'Element' list with the arrow keys, it takes about 1 second for the 'Color' swatch to fade between the colors. this makes finding a particular color swatch a somewhat slow process. making the swatch fade states immediately would be a help here.