It highlights Sydney, Tokyo, London, and New York sessions with transparent background colors.
You are able to change session times, color, and transparency.
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.