Petal color is an important trait for both ornamental purposes and also for attracting pollinators. Here, we report a mutation ofBrassica rapaR-o-18 with pale yellow petals that we retrieved from an EMS population and namedwhiter shade of pale(wsp). Phenotypic segregation ratio of an F2 mapping population indicates the phenotype is controlled by a single recessive gene. Mapping data from the whole genome sequencing coupled with allele frequency analysis suggests the mutation is located in a ~2 Mbp interval on chromosome 2. The interval contains a putative esterase/lipase/thioesterase protein previously demonstrated to account for floral color inB. rapa. We demonstrate thatwspcarries a G to A missense mutation causing an aspartate to asparagine substitution within the putative lysophospholipid acyltransferase domain.