As far as I have observed, Tikiapara aur Liluah k trains ka Tb alag hota ha. Tikiapara wale Lhb train ka TB usually red hota ha like Agnibina, CF, Lalkuan, poorva, Anvt biweekly, etc aur conventional rake wale ka blue like Vibhuti, Toofan, Bagh, etc. Aur Liluah wale trains ka TB yellow hota ha like Himgiri, Asr exp, Asr mail, Saraighat, etc