This invention relates to compositions of matter formulated to work in conjunction with CO2 gas for identifying the exact leak site location of small and large leaks in sealed systems. The leak finding compositions of matter foam, or are in the form of a foam, when applied to the one or more external surfaces of a system, that is closed and pressurized with CO2, where a leak site location is suspected. This foam then changes color from a first color to a second color over the exact leak site.