Can drugs be detected if the swab doesn't turn blue?

If a drug test swab does not turn blue, it may indicate a negative result for the specific substances being tested. However, it’s essential to consider that not all drug tests use colorimetric indicators, and some drugs might not be detectable depending on the test's sensitivity or the drugs' presence in the system. Additionally, factors like the timing of the test and the individual's metabolism can affect detection. It's best to consult the testing guidelines for accurate interpretation.