Direxxion Daily has both 'bear' and 'bull' oil ETFs. This tracks the volume in both combined. It also tracks them individually: the bear ETF is the red line, and bull the green.
NOTE: the color of the volume bars is determined by whatever ticker you're currently looking at, and whether current close is gt/lt previous close. It is intended to be used while looking at the USOIL chart. The colors will be inverted if you're looking at the 'bear' ETF! as the higher closes will actually mean price is going down :D
Note: I didn't know at the time how to add the script to the main screen so it opens in it's own sub-window. If you want it to look like the other volume, placed at bottom of main candlestick window, you can click and drag it into that window. Enjoy