The first pink pigmented grapefruit variety, Foster, was discovered in Florida in 1907 as a budsport of Walters grapefruit. The second, Thompson Pink, was also found in Florida in 1913 as a budsport on a Marsh tree. Both Marsh and Walters are derived from Duncan grapefruit. Thompson grapefruit was planted in south Texas where it produced two budsports with indistinguishable darker pink pigmented fruits, Ruby Red in 1929, and Redblush in 1931; these two were later widely planted in Texas, Florida and elsewhere. Further Thompson budsports lead to other minor darker varieties, such as Shambar (California), and Burgundy (Florida). Induced radiation mutants were produced from two Texas sources; irradiated seed of Hudson, a dark red seedy variety derived from a Foster Seedless budsport, lead to Star Ruby grapefruit (1959), and irradiated nucellar Ruby Red budwood produced the non-commercial A&I 1-48 (1971), which in turn produced a darker budsport, Rio Red (1976), the main variety now grown in Texas and Mexico. Further variety development has produced several other dark red varieties: Ray Ruby, a Redblush budsport (Texas, 1970); Flame, a Henderson seedling (Florida, 1983); Nel Ruby, a Ray Ruby seedling (South Africa, 1987); Rouge La Toma, a Ruby Red budsport, and its own seedling, Oran Red (Argentina, 1989). Because Rio Red has some shape and late season external appearance drawbacks, an active program to find alternative varieties for Texas has been initiated. Budwood and/or seed from varieties developed elsewhere have been introduced, new budsports discovered on A&I 1-48 trees are being tested, plants from fruit chimeras and chromosome transfer have been established, and irradiation of budwood, seed and tissue culture of several varieties has been carried out.