Fair Isle Leggings

I would like to make a pair that look something like this. This is a photo of my legs squeezed into the arms of a slightly too snug hooded sweatshirt.  Since I haven't been wearing this sweatshirt anyway, I am going to take it apart and see if I have enough material to make a full pair of leggings for myself.  I think with some brown boots and a tunic it might look cute and less pajama-y.