CME Trading Hours Highlight

Display the times when the CME is or isn't trading, on a non-CME symbol.
The Chicago Mercantile Exchange hours are usually from 17:00 one day to 16:00 the next, with an hour's break. Trading halts from Friday evening to Sunday evening. The exchange is in Chicago.
You might want to display these hours if you trade the same asset on a different exchange. For example, you might want to overlay the CME BTC1! hours on a Coinbase BTC chart to see how trading in these futures contracts affects the market.
Inputs:

• Shade Outside Trading Hours - If selected (the default), then the chart background is shaded when the CME is closed. If unselected, the background is shaded when it's open.
  
• Highlight Color - The colour to use for the background shade.
  

Just for fun, I wanted to publish a useful script that only took up one line 😁