I'm late to the latke party, but in addition to sour cream in the batter, I've found that a small amount of dry potato buds (instant mashed potato) prevents the batter from turning brown. It also helps get excess moisture and decreases the time for draining, As I grate ( The best texture comes from using an old fashion "safety" grater - looks like a rectangular paddle with stainless steel mesh. Saves from flavoring the batter with skin and blood as well.) I sprinkle a small amount (tsp?) over the batter as I add a couple of grated potatoes. If the grated potatoes are too wet (rushed the draining), mix in additional small amount, rather than flour. Matzo meal optional. Can leave in fridge several hours without too much darkening.