separated by colour / you can differentiate by colour / colour-coded
In part of the city, the train carriages are colour-coded by route so that people don't accidentally get on the wrong trains.
「色分け」＝ separated by colour / you can differentiate by colour / colour-coded
「都市の一部の列車は路線毎に車両が色分けされており、乗り間違いを防ぐことができる。」＝ In part of the city, the train carriages are colour-coded by route so that people don't accidentally get on the wrong trains.
ボキャブラリー
part of the city ＝ 都市の一部
train carriage ＝ 車両
colour-coded ＝ 色分け
route ＝ 路線毎
so that ＝ ～ように
accidentally ＝ 間違って
get on the wrong train ＝ 違う電車に乗ってしまう
イギリス 
