You don’t need a script to display a dual green/red or red/blue shiftlights,
1) open the Advanced panel,
2) set your SHIFTLIGHTS METHOD method to 2 (percentage)
3) double-click RPM THRESHOLD PERCENTAGE to see the sliders and just shift left all values and set blue led to zero

See the FAQ here to learn how to change RPM curve

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Here is 2 screenshots above with Cadillac cts-v with custom dual led green/red shiftlights in action.

Here is 4 QUICK screenshots of the iRacing Riley Daytona Prototype car with a custom dual led red/blue shiftlights in action.

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Posted in: 6 Setup And Configuration