Spinel has a pink complexion, magenta eyes, a small pointy nose, and cerise hair that is styled into a pair of spiky pigtails. She also has three black lines underneath both of her eyes, an inversion of the eyelashes from her original form and reminiscent of running mascara. Her clothing consists of a plum-colored top, puffy pointed hot pink sleeves, puffy rose shorts, hot pink wrist-length gloves, white stockings, and a pair of rose knee-high pointy boots.
Her gemstone is located in the center of her chest, cut in the shape of an upside-down heart with lots of facets and detail. When reset to her original self with her own rejuvenator, Spinel's overall design is shorter and rounded in contrast to her current taller and pointier design. She had black cartoonish eyes with three visible eyelashes on each, and her hair was styled into a pair of heart-shaped buns. Her top was white with more rounded pink sleeves and her boots become a pair of big magenta shoes. Spinel's previous color palette is also brighter than her current one which uses darker tones. Overall, her appearance was similar to that of a 1930s rubber hose cartoon character.
Her gemstone used to be right side up, resembling a normal heart.