yScer\FRT.enh-; yunspecified flies have a body color score or 2-3/5 (where 1 is y- and 5 is wild-type) for all insertions characterised. yScer\FRT.enh-; yP1\loxP.pro-; yunspecified flies have a body color score of 4/5 (where 1 is y- and 5 is wild-type) as long as yScer\FRT.enh- & yP1\loxP.pro- share a homologous chromosomal insertion point. If they do not, the resulting body color is indistinguishable from that of yScer\FRT.enh-; yunspecified animals.