I am really liking the yellow shirt, sadly I have not been able to get good results from yellow yet so a bit envious there!
In regard to the Yellow, here’s what I used:-
Basecoat = Scale75 Sahara Yellow (took three or four thin coats over Vallejo grey airbrush primer)
Highlighting = Vallejo Model Colour Yellow Ochre 50/50 with Basecoat
2nd highlight = Vallejo Model Colour Yellow Ochre
1st shadow = Vallejo Model Colour Ochre Brown 50/50 with Basecoat.
2nd shadow = Vallejo Model Colour Ochre Brown.
Tidied up where needed (accidents do happen)
additional highlights built up with Vallejo Model Colour Yellow Ochre and slowly adding Vallejo Model Colour Ivory.
So I hope that helps you.