So I mentioned I spent some time as a Trackman on the B&O. That experience taught me that turnout ties were not often replaced at the same time as regular ties. Those standard ties were much more available for track gangs to replace and of course there are so many more compared to switch ties.
I mention this as there are some prototype reasons why switch ties look different from all the rest as far as weathering and condition. At least on a well maintained line. It is not unusual for the longer switch ties to all be of similar age, while the standard ties around them may vary in age. The standard ties are replaced as needed, while a turnout would be repaired more likely as a unit with most or all ties being replaced. This is a factor in weathering for a model railroad. The rail on the other hand may be laid at a different times, but it’s weathering for modeling purposes is more uniform as it lasts much, much longer than a wood tie. Although turnout rail is replaced as a unit usually also, the intervals are just much longer. A Track Foreman or Track Supervisor will gauge turnouts and oversee construction, a lowly Trackman can gauge other track and spike it. Speaking from experience.
My modeling project is using Micro Engineering products and the track I bought is pre-weathered, though the turnouts do not come pre-weathered. Based on my earlier statements, I believe I should weather the rail similar to most of the rail in proximity, while the ties can be less uniform, for good reason.
One way to weather rail is to paint, another option is to use a chemical “blackening solution”. I was satisfied with several applications of Micro Engineering (ME) Rail Weathering Solution #49-103 as it turned the turnout rails a dark shade and matches the pre-weathered rail ME offers. Older rail, before the advent of roller bearings on freight cars, weathered a dark, dark gray stained by the grease from wheel bearings. Rail in more modern times often has a hint of surface rust and brake shoe dust that makes it appear a lighter, more orange color. Except maybe near rail lubricators that keep it a more dark gray color.
If you zoom in on the layout photo (I did that below) at the top of the post you can see that I have added joint bars and cuts in the track at prototypical distances on the rails. I still need to add a little chalk weathering and finish the ballast details, but the track work is coming together. Its a detail that we often pass over and getting it to match your prototype can help complete the scene.