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
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.