First of all, the colour error may be caused by "Hardware texture compression", an option in Trainz Content Manager, which is active by default. Switch it off an re-import the objects.
zygraal wrote:
I do to use the menu "GeoReference corner with map only" instead of "GeoReference google earth image"
Why? I recommend to use the automated functions wherever possible. Manual geo-referencing is always subject to error.
zygraal wrote:
and in addition they do not follow the terrain.
UTM tiles are hovering flat texture carrying objects. You can raise or lower them in Surveyor but they will remain flat. I suggest to always apply a ground texture for your TransDEM-based Trainz route, as explained in the manual. Use a cartographic maps as the source, like a Map Tile service. The ground texture will help you to find your way around and it will also be shown in the minimap.
(For a more advanced ground texture you can download topographic map clippings from
Géoportail. These would then indeed require manual georeferencing.)