Many CD 151 H.G. Co. /Petticoat insulators were used on the Chicago, Rock Island & Pacific Railroad as it ran East and West through Iowa. Most were various aqua and blue aqua colors; however, there were a few that were near clear in color. I also found the CD 151 H.G. Co. /Petticoat in rare colors including corn-flower blue and depression green. This post shows a depression green CD 151 which was found in late April of 1973. It was found on a section of telegraph line located East of Moscow, Iowa a short distance from Witton, Iowa. Details on the back of this insulator are as follows:

CD-151 H.G. Co. (Front Skirt) / Petticoat (Back Skirt) - Depression Green - Measures: 88mm Wide x 104mm Height