The 3 used have default lengths 72, 305 and 1292, calculated after the first length default value of 72. For each of the 3 only an upper line, set by default at 78.6%, is plotted in green and its complement, set to 21.4%, is plotted in red. When the closing price is above 3 green lines, we say it is Forbidden to Sell ( PV ), and when the closing price is below 3 red lines, we say it is Forbidden to Buy ( PC ). Those conditions are flagged on the chart. These PV-PC conditions were, up to my knowledge, first proposed by Bo Williams.
Fibonacci's retracements are show for the Channel with length 72 by default, but it can be changed to any length. They are colored as fuchsia (100%), blue (127%), orange (162%), yellow (200%) and navy (262%).
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.