hair color changing

Attached are pics of my 11wk old Nigerian dwarf buck (currently and some to reference from when he was younger.) He started having silver hair sprout randomly within last few days, I did treat both my goats for lice which are now gone about a week ago (with cylence 1mL to neck/back) could this...

My lovely milk chocolate brown Nigerian doe started shedding about a week ago, she looked fine before then. Her new hair is coming in white, dull, is very thin and pulls out easily. She has a lot of dandruff but doesn't seem particularly itchy. She is eating well and seems normal, otherwise...