A preliminary color test can be used to screen a particular drug found at a crime scene. These screening tests can help classify the TYPE of drug found, but not confirm the exact drug found Match the following tests to one or more drugs that it can be used to screen for. Marquis test turns purple in the presence of Marquis test turns orange or brown in the presence of square . [Choose] [Choose] Cocaine Marijuana barbiturates LSD Amphetamines and methamphet.mines square Dille-Kopanyi test turns violet or blue in the presence of Duquenois-Levine with chloroform added test turns purple in the presence of Van-Urk test turns purple or blue in the presence of square The Scott Test (with cobalt thiocyanate) turns blue in the presence of square more