I want to have a fuel dip stick that is mildly flexible to pass a curve in the filler tube. I have tried the metal tape from a typical retractable ruler like most of use, and that works, but I cannot see the fuel level on the metal. I have tried blackening the tape with Pro Seal and a few other things that are fuel resistant, but have not found something readily available to use. I can't see the fuel level with anything I have tried so far. Some sort of thermal paste that changes color would be perfect if commonly available.

An ideas out there?