To provide a method for changing the flower color of a moth orchid, particularly a method for producing a moth orchid having a red or reddish flower color from a white moth orchid.A method for producing a moth orchid having a modified flower color, which comprises transfecting a moth orchid with a gene encoding a flavanone 3-hydroxylase, a gene encoding a flavonoid 3′-hydroxylase, a gene encoding a dihydroflavonol 4-reductase and a gene encoding an anthocyanidin synthase and expressing the genes.
