How do I use one wild and one yellow train for a gray route that is two train lengths long

[please join me]

I'm worried that if I have 7 yellow and 5 wild, the interface will use 2 yellow or 2 wild, then I won't have the right combinations for the rest of my routes. When I click on the route, if I pick yellow, it will use 2 yellow, and if I pick wild, it will use 2 wild. This is not what I want to do. How do I do it. It's really an interface question.

[SiRan90]

Ifni remember right you can select the cards in your hand first and then click the route and it will use them cards

[Ceaseless]

I'm worried that if I have 7 yellow and 5 wild, the interface will use 2 yellow or 2 wild, then I won't have the right combinations for the rest of my routes. When I click on the route, if I pick yellow, it will use 2 yellow, and if I pick wild, it will use 2 wild. This is not what I want to do. How do I do it. It's really an interface question.

How exactly do you plan on not having the right combination for the rest of your routes if you use 2 yellow?

[ExaltedAngel]

In USA or Europe (or on any other map where locomotives are used normally), not being able to choose arbitrary combinations of coloured cards and locomotives is not a problem under any circumstances.
In Switzerland, however, this is a known and already discussed incorrect implementation. I tried to contact the developer, and there is a dedicated thread about it on the TTR Maps subforum, as well as a bug report, which unfortunately was not accepted. Hopefully, the issue will be resolved sooner or later.