The purple area is the Daily December Futures contract subtracted by the current price.
The blue area is the Daily September futures contract subtracted by the current price.
The green area is the Daily June futures contract subtracted by the current price.
You can use this to try and understand market sentiment.
If the current price dumps but the premium remains the same it likely means that sentiment is unchanged.
The opposite is true, if the price pumps and the premium is the same it means the market likely wasn't convinced by the movement.
The difference between the current price and the futures price can help determine how bullish or bearish a market or at extremes the level of euphoria.
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.