Tree coverage is not yet correct, basically it guesses tree occurrence by when the vegetation index value goes over a threshold, which isn't entirely right. For example, coniferous trees have a lower vegetation index than broad leaf trees and some bushes, so the coverage yields some false values especially near the (arbitrarily chosen) tree threshold. There will be a better dataset that specifically identifies trees and brushes, along with tree types; this here is the initial biome support version.
Colors - yes it's using compiled Blue Marble data, the problem is that the colors there do not represent raw color values, but were manipulated to make them fit into a single color map. It's non-linear, and we need to apply a reverse transformation - this too is subject to further evolution.
The server apparently can't handle the amount of downloads, and the speed also greatly varies around the world. We'll be moving the servers to Google cloud that should help with that. Also debugging why the app deletes the downloaded data ...
