The “dressed chandelier” made its appearance after 1740. The English in particular favored heavily-draped fixtures with multiple swags of crystal buttons, for it was the skillful pastime of stylish ladies to redress the swags and pendants in different arrangements. When new prism shapes were introduced, chandeliers were often redressed in the latest fashionable taste.
Colorful or uniquely patterned glass diffusers are typically hand made and, as such, will exhibit some variation in both color and pattern.
Such variations should be considered normal and indicative of hand crafting rather than machine production.