A mock-up was manufactured in Japan after Kawasaki Heavy Industries won the contract. It was shipped to Singapore and put on public display during the 1984 National Exhibition held in November 1984 at World Trade Centre. The mock-up featured three choices of seating arrangements and colour schemes; members of the public were invited to give feedback on these options. The finalised interior design of the C151 trains consisted of a fully longitudinal seating arrangement. The bucket seats were made of plastic; glass partitions separated the seating areas from the passenger doors. Strap lines for standing passengers were installed in the middle of every car. The colour scheme of each adjacent car's interior is distinct to make car identification in cases of fault reporting easier for passengers. Originally the colour scheme of the driving trailer cars was orange, that of the second and fifth motor cars was blue, and that of the two centre motor cars was green. There were nine seats between two doors; this was reduced to seven after the first round of refurbishment.