Valky, I don't know much about Deus Ex style exactly (how it could be done in Thief) but colored lighting was implemented in Thief 2 and is in the lots of FMs for T2. Maybe I misunderstood you. As for stylistic similarities - I honestly don't know much. i've said about train mission in T2X and Konrad told you about Patriot (it's a hard campaign as I heard).
And - if you want to experience some stylistic or plot parallels between DX and Thief in Thief fan-missions (though it is really une...
Well we already have a train mission in Zontik's Patriot campaign:
https://www.thiefguild.com/fanmissions/9350/patriot
The train is rather short and it's a cargo train. The mission is quite linear, too. Thus I agree with you that something more sophisticated would certainly be fun. Some time ago, I've seen somebody working on a project like this. I remember screenshots, but I forgot who that was now. Anyway, passenger trains are an excellent place for criminal stories, pickpockets and big...
Very well put, at first I didn't understand why there was so much praise for this mission and I actually started to move onto another mission but multiple people recommended it when I was looking for a recommendation of which one to try first (I played Feast and Builders Paradise first and both were long, involved missions).