Customization Help

hello, i need help from anyone who can with this situation please. if you notice on this site, the menu to the right has those dotted borders horizontally and vertically to seperate everything. well, on my site, Making Sense. I have made the horizontal seperators yellow to match my site. by using a small yellow dot in the form of a jpg and simply stretching the image. well, i tried to make the vertical line yellow as well, but no matter what i have tried, i cannot seem to do it. if you please look at my site, you will see that the vertical line is still the original default type. does anyone know how i can change that vertical line so it looks like the horizontal yellow one's? i would appreciate your help oh so very much. thank you for your time.