The fruit has a yellow rind and distinguishes itself from other Marsh varieties by a red blush that covers parts of the rind. A dark pink blush in the peel and an intense deep red flesh characterizes the fruit. Fruit size is smaller than Ray Ruby and Rio Red. The peel has a smoother texture than other grapefruit varieties. Juice sacs have a crisp texture not found in other grapefruit varieties.
Trees are less cold hardy and are more susceptible to footrot.
Production of Star Ruby is often disappointing due to low yields. Conservation problems often occur in late shipments and rainy seasons Flame Flames were selected from Ruby Red for color characteristics. The fruit peel has a darker pink blush than the Ruby Red but less than that of the Star Ruby. The intensity of the blush is about the same as that of the Ray Ruby and the Rio Red. The flesh color is significantly darker than that of the Ruby Red, slightly darker than Ray Ruby, and slightly lighter than Rio Red.