Technical Abstract: Seven sticky rectangle traps of various yellow colours and fluorescence made of cardboard were field tested against western cherry fruit fly, Rhagoletis indifferens Curran, in paired trap preference experiments in Washington state, USA. Alpha Scents (proprietary paint), Fluorescent Yellow (aerosol paint), Saffron Thread, Neon Light, Macaw, Citrus Splash, and Lemon Zest (all semi-gloss enamel) traps were tested. The Saffron Thread and Citrus Splash traps, which were very yellow with low fluorescence, were similarly preferred by R. indifferens and one or the other was preferred over the Fluorescent Yellow trap, which was yellower but had much higher fluorescence, and Neon Light and Macaw traps, which were less yellow than Saffron and Citrus Splash traps. The Citrus Splash trap was slightly more preferred than the less yellow Lemon Zest trap. Saffron Thread and Citrus Splash traps captured more R. indifferens than the Alpha Scents trap, but non-target muscoid flies preferred the Alpha Scents trap and their high numbers likely reduced catches of and obscured any preference for it by R. indifferens. Saffron Thread and Citrus Splash traps caught relatively few non-target muscoid flies and were more selective than the Alpha Scents trap. Results suggest that sticky rectangle traps painted semi-gloss enamel Saffron Thread or Citrus Splash with low fluorescence could be highly useful for detecting R. indifferens.