VerticalSim has released a freeware package called VOrthoAutogen. This is an addition to their Vstates series, which improves the visuals of autogen on ground.
In a summary, this autogen package erases all ugly XP11 shades of green under the autogen buidlings (gardens behind some houses.) It is the best to use with ortho, however, it is also usable without it. The main use of this package, as described, is for VerticalSim’s VStates sceneries.
Here are two screenshots, so you can compare the difference. The source of these screenshots: VerticalSim Facebook