Complex sentence: Very recently in late 2015/early 2016, a white version of the'Black Widow' kit called the'White Widow' was introduced, the shell color being the only differentiating factor between the two kits.
Split into simpler sentences: Very recently in late 2015/early 2016, a White version of the'Black Widow' kit called the'White Widow' was introduced. The shell color being the only differentiating factor between the two kits.