There are 2 indicators. One is used for a small timeframe, and the second for bigger timeframe.
Red line = small-timeframe (default 1 hour)
Blue line = big-timeframe (default 1 day)
If big-timeframe less than 30 and at the same time small-timeframe less than 30, then it is very probable market bottom. Then there is a lime background.
The user can change timeframes and the periods. And the limit.