>>8998851Because engineering and budget simply weren't there. That kit is 20 years old and cost a mere 500 yen, it came out the same year as the very first HGUC RX-78-2. While they were starting to make some improvements, SDs in that era were still generally not very well engineered, and were more like a cute little afterthought than anything else. Nobody really cared about making them look perfect, and some of them got molded in only two colors of plastic. Shit, you should be grateful if anything, you got four colors on that Guncannon, including a clear visor.
