Also, built it so you could change the values that give the red and green signals. Default values are 0% or less (backwardation) indicates green. However, i found that a 0.5% setting worked will finding local bottoms for current contract of XBTH20 (March 2020). The upper value default is at 5%, and signals red when the next contract reaches over 5%.
My assumption is as BTC increases in value over time, measuring contango in terms of percent will be a better measure of the XBT curve.
Also updated to version 4 pine script
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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.