All that glisters is not gold. Nevertheless, what most people say is "glitters." It's the singular, because it's kind of a reverse formation: gold is not all [the only thing that] glitters.

: to be brilliantly attractive, lavish, or spectacular. also : to be superficially attractive or exciting. glitter.

Glitter is commonly used in arts and crafts to color, accessorise and texture items. The small, brightly colored particles often stick to clothing, skin, and furniture, and can be difficult to remove. It is also used on optically variable inks.

glitter (countable and uncountable, plural glitters) A bright, sparkling light; shininess or brilliance.