Welcome to the forums.
What you seem to have there is a texture compression problem (which caused multicolour textures).
I do have a fix available for this - it's in the thread in my signature. However, you need to register your version with N3V first - this can be done by clicking Planet Auran above, then click Serial Number, then fill in the form. This is so users can identify what version of Trainz you have, as the fix only applies to certain Trainz versions.
Shane
