Snow Melange v20 cm

"Rosa Snow Melange" is likely a misremembered name for a rose variety; common "snow" or "melange" related roses include Rosa 'Snow Meillandina', a white miniature rose, or cut flower varieties like Rosa Melange, a pink/salmon cut flower with a short stem. Another possibility is a variety of Helleborus (Snow Rose), which are winter-flowering plants with white, pink, or cream blooms and are sometimes referred to as "Rosa" due to their rose-like appearance, such as HGC® Snow Dance®. 
If you're looking for a garden rose:
Rosa 'Snow Meillandina': This is a miniature rose with white, double flowers, created by Meilland in France. 
Rosa Melange (cut flower): This is a cut flower rose with pink/salmon colors and shorter stems, available for wholesale. 
If you're looking for a winter-flowering plant: 
Snow Roses (Helleborus): These are winter-flowering plants that bloom from December to March and are known for their white, pink, or cream-colored flowers. Varieties like HGC® Snow Dance® (white) and HGC® Shooting Star® (pale pink) are examples from this group.
To find the exact plant you're looking for, consider its size, flowering time, color, and if it is for a garden or for cut flowers.