This is the typical Relative Strength Index indicator with two moving averages, one slow (length 50 by default) and one fast (length 20 by default). Additionally, there are four lines, which mark the oversold/overbought signals at different levels, there are two inner bands with values at the levels 40, and 60, and two outer bands at the levels 20, and 80. The presence of the fast and slow moving averages and their crossover/crossunder with the oversold/overbought levels or the RSI can provide more insightful and faster signals. The indicator has a slightly different colouring mechanism.
The views of the RSI indicator on the above the price chart in both dark and light modes: