Like a holographic sticker changing color as it catches the light, rainbow patches and tiny sparkles drift across the surface.
`hueShift` rotates the rainbow colors. Raise `foilScale` for smaller, busier color patches; lower `saturation` for a more silver finish. `crinkle` adds wrinkles to the foil, while `sparkle` changes how many glitter flakes catch the light.
The effect creates its own foil surface, making it useful for badges and sticker-like graphics. Moving sparkles and color contrast can obscure small text, so avoid applying it to whole paragraphs.
When to use
Use it for stickers, limited-edition badges, or a foil accent on packaging. Avoid it across long copy or large areas of a restrained interface.