The bright red and blue combination are great for visiblity. Clean and uncluttered, the Underground logo gets its message across very directly. Contrast this with NYC's globes, which are either red or green (and so totally useless for red-green colorblind people like me).
by 67ideas

When in London for the first time, being able to spot and recognize these logos from a long way off is an absolute God send. Plus, it's just a cool-looking logo.
by joshwritescopy