First will preface this with it is your model rr and you can do what you like/want!
But, as apennvsy fan can't hold my thoughts.
The Pennsy never had any Tuscan Red freight engines (including F-Units). They did have one and only Baldwin VO-1000 painted Tuscan Red road number 5919 for the Sunnyside Yard NYC. And maybe a red GG1 moved freight sometime or other.?
Mixed in this shot is MTH's rendition of that VO-1000 Number 5919.
Ron