The pictured Hoya 49 Green Filter , originally $ 37.25 drops from $22.35 to $19.35 . Also checkout other products: Hoya 49mm X1 Multi Coated Filter, Green, and FreeShipping. Bonus: No sales tax either, unless you live in New York or New Jersey.
Filters are similar to half-color, except that color density gradually decreases near the center of the filter allowing emphasis of foregrounds or backgrounds.
Mounted in a rotating frame, 7 colors are available: Pink, Yellow, Emerald, Tobacco, Blue, Mauve, Gray.
Their color gradually fades out so the boundary between the colored and transparent sections will not become apparent even with the lens aperture stopped down.