Playful Palette is a color picker interface for digital paint programs that derives intuition from oil and watercolor palettes, but extends them with digital features. The palette is compactly parameterized as a set of color blobs that blend together to create gradients and gamuts. They can be directly manipulated to explore arrangements and harmonies. All edits are non-destructive, and an infinite history allows previous palettes to be revisited and modified, recoloring the painting. This design is motivated by a pilot study of how artists use paint palettes, and is evaluated with another group of traditional and digital artists to demonstrate Playful Palette's effectiveness at enabling artists’ color tasks, and at amplifying their creativity.