Complex sentence: They contain long, soft fur which is typically gray mixed with coarser reddish brown hairs on the dorsal side, while on the ventral side, the hairs display more of a grayish white tone with some brown mixed in.
Split into simpler sentences: They contain long, soft fur which is typically gray mixed with coarser reddish brown hairs on the dorsal side. On the ventral side, the hairs have a grayish white tone with some brown mixed in.