From Looney Pyramid Games Wiki

Purple is a translucent color of pyramid, first introduced in late 2001 at the same time as orange pyramids. It is considered to be in the "Xeno" family of colors. It was first sold in clear tubes of 15 orange pieces. The tubes bore the phrase ICEHOUSE PIECES and no game in particular was advertised to the buyer. The first actual game to feature purple pyramids was Treehouse, in the Xeno Treehouse tube.

Contents of Purple Icehouse Pieces tube

Contents of Xeno Treehouse tube