We have already realized the mistake in colour for the feed tank and changed at our end. I will upload it. 

Cable trays are in your scope hence Red.  The purpose of showing it in our layout was to give you idea of how it can be routed. You can plan your own route. 

Based on the overall layout, the ilocation of instruments and pumps,  you have to plan your cable routing for instrument and electrical cables and decide about the cable trays.   