I actually bought the Region 4 GOUT (took advantage of a glitch with CD WOW's site that let me order the DVDs with a massive discount). These discs come in clear cases, it's just a shame about the huge "PG" rating obscuring the cover artwork.
DVDs in clear cases are pretty common over here, and kids DVDs quite often come in yellow, blue or white. All Xbox games are in green cases, and Wii games have white cases.
Will stop now before you all slip into a coma. :)