In this CSS Hackz Series article, he outline several solutions for displaying alpha-transparent PNG (a.k.a. PNG-24 format) images in everybody’s favorite broken browser, Internet Explorer. Specifically, IE versions through 6 (excluding IE 5 for Mac) fail to support alpha-channel transparency for PNG images. In these versions of IE, every pixel containing alpha-transparency is displayed with an ugly, flat gray color. PNG Fix for Internet Explorer