Observed variations in the hue of reagents used in immediate drug screening processes serve as a visual indicator of test results. For example, a specific shift to blue within a testing cassette might signify the presence of a particular substance above a pre-defined threshold, whereas another color could denote a negative reading or an invalid test.
These visual cues provide a rapid and easily understandable method for preliminary assessment, enabling immediate action in time-sensitive scenarios. Historically, these color-based systems have increased efficiency in workplace safety programs and law enforcement procedures by offering a readily available result prior to laboratory confirmation.