It helps distinguish them. Seeing all numbers as e.g. black vinyl makes them blend together in my memory.
Visualizing something lets you leverage visual and spatial memory, but even then: if I were really running past N real giant numbers which all looked identical, I'd lose track just the same. Distinguishing them visually makes them all unique and memorable. The color infuses the entire track and the sky, actually, so it requires little focus, because it's right there in the background.
Basically like the memory palace from Moonwalking with Einstein, but less work, because they don't have to be consistent over time.
