Bill Williams Zone and Squat Bars. See New Trading Dimensions by Bill Williams, PhD. Bars are green (green zone) when the Awesome Oscillator and Accelerator/Decelerator are both positive. Bars are red (red zone) when the Awesome Oscillator and Accelerator/Decelerator are both negative. Bars are blue when a squat bar is formed, these indicate a battle between bulls and bears and often happen near trend continuation or trend changes. Caution: Assumes chart is a bar chart - not a candle chart. Caution: Squat bars are accurate only with official exchange volume data - BATS data will give false squat bars.