re-post #4674 smyers
If you wish to disable the numbers, try on a clone. In the config, delete the container "default" and what it contains, now rename the tag "body" to "default", exit and save the config.
However if you require the running numbers then in the config, just look for the container "vehicle-running numbers" and choose what you wish to amend. You will need to change the alpha numbers to the required colour. Both loco and tender need to be altered, but of course use clones. As with the latest models now appearing; it it not always easy or possible to make changes. Best of luck, no CTD hopefully.
Cheers, evilcrow