Have a coloring question.   having to redo my old yard to upgrade it to proto standards

Originally laid about 1997....the ballast is too dark and need to color the ties and rail properly.   not sure how to adjust what I'm doing to get more realistic.   The prototype is circa 1980....during bad maintenance times, but a class 1 railroad and a semi-large proto yard.   My yard isn't that big, so I'm doing this by hand with brushes.  Doesn't have to be perfect, but want proper coloring, and to look good during photos as well as in person.   The track looks better in person, but it is sloppy right now....just testing coloring and techniques.

First pic is the before pic:

Next pic is after brushing over with a white gesso wash.  this is primarily for lightening the ballast to a whitish grey

not worried about the rust spots as they will be painted over.    The next two shots are after basic painting.   trying to decide about tie color.   think I am leaning toward the 'blacker' tie color to differentiate more from the rail color.   using wally world acrylics right now as they are cheap and readily available.   which color is more 'proper'? ha ha.   also, is there any other colors for the ties or techniques to make them better looking.    I don't want decrepit, but well used.   I can't spend a minute per tie as well.

Picture two here has more brown in the tie mix.  Think it washes out a little more with the rail color.

As for the rail color, this is acrylic chocolate brown.  It is obviously too consistant.   needs a little more variation to it.   not sure if I want to use any chalk on it or not.    What does everyone else use?    for most of the rest of the layout, it will be newish flex track and turnouts....plan on just spraying it with rail brown polly scale

any thoughts are welcome.

thanks in advance,