need help with making a clear border

i have a window blind that i have intalled. i like the blind, however, i want to do some adjustments. Currently, all my windows have a clear border around them when not maximized. I really like the look, but would like to increase the size of just the clear/transparent area. I just got SkinStudio today so that i can play around with it. however, after spending a hour or so messing around trying to figure it out myself, i can't figure it out. if anyone know, please advise.

also, is it possible to keep the clear border around when an active window is maximized. Thanks