UAS regulatory sequences drive expression of a hairpin RNA that targets the EGFP fluorescent protein and a number of its derivatives (ECFP, EYFP and YFP-2) but does not target plain GFP. The hairpin was made using the following oligos - forward: ctagcagtCAAGGACGACGGCAACTACAAtagttatattcaagcataTTGTAGTTGCCGTCGTCCTTGgcg, reverse: aattcgcCAAGGACGACGGCAACTACAAtatgcttgaatataactaTTGTAGTTGCCGTCGTCCTTGactg.