In summer squash (Cucurbita pepo), fruit colour is determined by two independently assorting genes, $W/w$ and $Y/y$, which exhibit dominant epistasis. The biochemical pathway is shown in the diagram below:

A plant breeder crosses two double-heterozygous squash plants ($WwYy\times WwYy$). If the cross yields 480 offspring, how many are expected to produce green fruit?