Hong Kong’s railway system (MTR) currently has nine lines, each denoted with a colour. The original system only had three lines with three easy to distinguish colours: red (Tsuen Wan), green (Kwun Tong) and blue (Island). When the system extended to Tseung Kwan O, purple was introduced, then to Tung Chung (orange). These were all distinct and easy to call by name. It became a little problematic when the Airport Express introduced a teal colour with a dot pattern. The hue is somewhere between the original blue and green lines. When the East, West and Ma On Shan railways were acquired from Kowloon–Canton Railways and merged with the existing MTR network, the colour coding problem was accentuated. The original East, West and Ma On Shan railways had no colour coding because they were standalone lines and not part of the same network. The light blue and fuchsia for the East and West Rail lines are particularly problematic. The fuchsia is too close to the purple, and can also easily confuse with the red and blue. (MTR system map, 1.3MB PDF)
The line colours are used extensively in the signage, though the application is sometimes inconsistent. The lines in the network and line diagrams are always in the respective colours. However, directional signage that points to platforms of two train directions use a coloured circle with a number inside, indicating the platform numbers. This symbolism is more commonly used to indicate line numbers, as it is true in Paris, Tokyo and Beijing. In fact, passengers do not need to know platform numbers in a metro system, as trains always leave from the same platform. It is also difficult to recognise the colours in the area of a small circle.
Another recent idea that the MTR has implemented is back- and front-lit directional signs with the line colour as the background colour at Tsim Sha Tsui/East Tsim Sha Tsui stations. The designer’s rationale might have been that the colour coding would be immediately apparent, as there is more of it on the sign. But users tend to notice the message rather than the background colour and unable to tell that it is a colour code. The fuchsia and red lines interchange at Tsim Sha Tsui station make it impossible to distinguish between them. The colour inconsistency on the back- and front-list versions further emphasises the problem.
The MTR stations in Hong Kong are rather colourful environments. Enamel panelling on the platforms of the older underground stations use a variety of colours. This was a useful design decision for passengers in crowded trains to immediately recognise which station the train is at. Colour panelling adds identity to otherwise undistinguished and monotonous underground stations, but tends to weaken the colour identity of each line. Above-ground stations do not have a need for this, as landmarks are visible from the windows. Though the company has decided to make above-ground stations consistent with the other stations after the rail merger. This is no doubt a branding move. The once blue-and-white signs for the above-ground stations have been replaced with a variety of pastel colours. They are aesthetically atrocious but also further weaken the line identities, not to mention camouflaging the information with the already busy outdoor environment.
My recommendation to MTR is to strengthen the line identities by reinforcing the colour coding system: consistently use coloured lines as the only graphic format for indicating the railway lines (lose the circles and platform numbers); implement a line and station numbering system (especially important for non-Chinese- or English-speaking visitors); ensure colour consistency and distinctiveness across different media (front-lit, back-lit, inkjet printed, screen printed, digital screens, etc.); and minimise the use of large varieties of colours for other things (for example patterns maybe used for station identity rather than relying on colours).
The MTR system is one of the most efficient and well managed mass transit systems in the world. When I ask visitors from overseas what they remember most of Hong Kong, a surprising number of people mention the MTR. The information design is already quite serviceable. There is no reason why it can’t be made even better and exemplary for the rest of the world.