The middle part of the bands are the gummy worm version of . It is the using the high and another using the low. The black line is HL2 (technically 3 VWAPs).
The bands follow what I was mentioning above. So the outer most part of the bands are the high & low (with the same multiplier) and the inner bands are the HL2 .
Of course you can set whatever input source you want for these. The default is how I use it. If you want to get rid of the bar color just go to the indicator settings and un-select it at the bottom.
Source code is open so feel free to poke around.
Hope this helps,
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.