This is an educational work and it's developed to show how to write scripts that will work like built-in volume indicator.
We have new features in Pine Script™ Language, such chart.bg_color, chart.fg_color, chart.left_visible_bar_time, chart.right_visible_bar_time and many more. Many Thanks to Tradingview and Pine Team for such great additions! You can find more information about these new functions here.
How the script works? - At the first step it calculates how many visible bar on the chart by using chart.right_visible_bar_time and chart.left_visible_bar_time functions. - Calculates the zero line for the volume - Finds maximum volume on visible area and normalize all volume values - Draws volume bars - Shows volume info as indicator value. in this step it uses chart.fg_color and plotarrow() commands to show the values in optimum color.
In order to place the indicator at the bottom of the chart, Please set Bottom Margin = 0 as shown in the following screenshot:
You can change the volume bar colors optionally.
An Example screenshot with different volume bar colors: