Silver Glitter gives the letters a bright white outline and packs silver glitter inside them. The fill deliberately does not go to pure white at its lightest point — white specks on a white fill are invisible, so it sits at a light grey with white flecks, which is what silver glitter actually looks like.
Want to change the colour, sparkle shape or glitter grain? Open the Glitter Text Generator — 16 palettes, 7 sparkle shapes and 8 sliders, all built on this same animation.
The outline is a second text element painted with paint-order="stroke" so the stroke sits behind the fill rather than eating into it, and the mask includes the stroke width so the glitter runs to the outer edge instead of stopping at the glyph. The specks themselves are the same thresholded-turbulence field the whole family uses.
Because pure white would hide the glitter. The palette tops out at a light grey precisely so the white specks inside the letters have something to read against.
Yes — the outline slider in the studio runs from none up to 8px, and it is applied to the mask as well as the stroke, so the glitter follows it.