Black vinyl, white label test pressing. Ten copies were pressed, all handnumbered, all came in white inner sleeves only. Seven copies, numbers 3-5 and 7-10, have been on eBay, all from the same seller. Number 6 may also have been sold by the same seller. The seller claimed to sell them for the Insipid Vinyl owner.
It may seem odd that the test pressing for a picture disc release is pressed on regular black vinyl, but it is actually common. The process of pressing picture discs is slightly different to pressing regular vinyl, and it is too expensive to set up the machine that sandwiches the images between three pieces of clear vinyl for a test pressing only. Doing it as a regular vinyl pressing tests the audio quality of stampers just as well. 
At the time, no pressing plant in Australia was capable of pressing picture discs , so the test pressings and retail singles were pressed in Los Angeles, USA . The plates were made by Lee Plating as seen from the L-codes, and may have been pressed by Erika Records.
The test pressings sold by the Insipid Vinyl owner from 2002 and on came with a signed certificate of authenticity (COA), all except copies 7 and 9 came on paper with a company letterhead. According to the COA, the test pressings were done as regular black vinyl pressings because the first set of film was not set to the appropriate DPI yet, and had to be redone. However, even if the film and printed papers were ready, the pressing plant would not have done the test pressing as a picture disc. There is no reason to have proper picture inserts on a test pressing as they are testing the audio, and the plant would only have done it as a picture disc if the record label absorbed the extra cost, which is fairly certain a small independent record label wouldn't do. The pressing plant could also just have used blank papers if Insipid insisted on a picture disc test pressing.
The COA also mentions that several test pressings were sent to band and management for approval. However, the first two auctions claimed that eight test pressings went to Nirvana, their management, and The Jesus Lizard, and only the two copies the seller had listed up until then were kept by Insipid. Over the following years the seller sold, or at least attempted to sell, all the seven copies shown in image 1. It is entirely possible that numbers 1 and 2 were sent to the bands and management, but time will tell.
1. Copy 3
2. Copy 4
3. Copy 5
4. Copy 7, side A
5. Copy 7, side B
6. Copy 8
7. Copy 9
8. Copy 10