Using Fabulously Optimised in Singleplayer, I've had some issues with snow turning blocks white, I read that it was because of this option but turning it to false doesn't seem to change anything
Solution
You can either: - increase vertical quality - it might help DH to separate the snow block from the rest of the structure - add every type of snow to ignored block (including fuill blocks) - this will remove any snow from all your LODs