- Go to "asset editor"
- Click on "base game"
- Choose any train (engine)
- At the bottom left click on "add variant"
- Choose the new variant that you made
- Choose any colors you want

- Right click on "voxel tycoon" > "properties" > "browse local files"
https://steamuserimages-a.akamaihd.net/ugc/2496767318598933106/81A3231C15724CA3F8A3D2C658FF965821B71E55/?imw=256&&ima=fit&impolicy=Letterbox&imcolor=%23000000&letterbox=false

- Or go to D:\SteamLibrary\steamapps\common\VoxelTycoon (this path may not always work)

- Go to "content" > "base" > "trains" > "units"

- Choose a train

- Open *.trainunit

- Find "liveries"

- Copy and paste this:

{
"gray": {
"NightLiveries": null,
"Meshes": {
"base/electric_engine_2.obj": "base/electric_engine_2.obj#gray"
}
}
},

https://steamuserimages-a.akamaihd.net/ugc/2496767318598991379/234D9922868FD6D0DFED8A5968D2A9B2C10797F1/?imw=256&&ima=fit&impolicy=Letterbox&imcolor=%23000000&letterbox=false

- Change "gray" to variant that exist in *.obj.meta

- Chagne "electric_engine_2.obj" to a object that you are editing

- If you want to add more than one:

{
"white": {
"NightLiveries": null,
"Meshes": {
"base/box_car_2.obj": "base/box_car_2.obj#white"
}
},
"blue": {
"NightLiveries": null,
"Meshes": {
"base/box_car_2.obj": "base/box_car_2.obj#blue"
}
},
"red": {
"NightLiveries": null,
"Meshes": {
"base/box_car_2.obj": "base/box_car_2.obj#red"
}
}
},

https://steamuserimages-a.akamaihd.net/ugc/2496767318598987177/9F68D9410E8AE29643EF37976158EB9C6434CA0F/?imw=256&&ima=fit&impolicy=Letterbox&imcolor=%23000000&letterbox=false