Recently we asked readers to choose their favorite color name for the Expo Line. While Aqua received the bulk of the votes, many readers suggested that maybe it was time to move away from color names to a naming convention that used numbers or letters instead. It’s a logical suggestion, and one that Metro has actually considered in the past.

In fact, in 2003, when Metro was first launching its new branding and logo, rail maps and schedules were introduced that featured rail lines labeled by their color names and letters. Here’s the legend from the 2003 map showing lines A, B, C and D:

This was a trial program that lasted for much of the year but was eventually scrapped due to complaints. Perhaps it was an idea that was ahead of its time, but it’s likely to be looked at again by Metro as the rail system grows.