This float has both Amber Green Swirls and Blue Swirls.  The amber swirls go around the equator and base.  The blue swirls emanate from the seal and extend out.

There may be a mark, too.  It's hard to be sure but there appears to be a raised check mark on the edge of the seal.  I've seen other check marks that are in the same location and same size.

It's also lightly frosted.

Measures 3 1/2 inches in diameter.

Found on a remote Alaskan beach.