I'm not sure how deep these lakes are but you may want to try sinking lines.
Chironomids and scuds are often things overlooked. Fishing these on a static line or even a super s-l-o-w strip work. Blobs are good stocker flies. Try brighter colors like everyone is suggesting. Most lake flies have a lot of motion in them. Long marabou tails and dubbing bodies.
Lakes are a mystery, every time you go to one it's like a new puzzle. Fast retrieves, slow retrieves, no retrieve? You never know. Find structure, weed beds, a little log, drop offs.