How to read mean returns (Expand the indicator)

Mean returns is a trend detection and overextension indicator. It oscillates around the value of 0. The mean return line in reality is the orange one as well as the blue one. The difference is in the number of data points into the past that they consider. Since the value of those lines is the expected value of the returns in period t, then if it's over 0 the expectation is that returns will be positive, as previously the price has been trending higher. The opposite being true as well.
Meanwhile, the red and green line represent the expected upwards and expected downwards returns. That means you only take the expected value for the days in which the return was positive or negative accordingly. Therefore, if the mean returns are over the expected upwards returns the price is likely to be overextended, and vice versa.

Other adjustments were made to consider the current candle. This code will remain private, as it took a lot of effort to invent. I hope you are able to understand the math. If you can't, I hope this at least allowed you to read the meaning of the indicator through this.