I'd also mention that black lasermarked white wire has marvelous contrast, even in the dim, covered in dust. Black lasermarked (or god help you, heatstamped) wire on damn near any other colour, like one finds in automotive, is distinctly worse.

Yellow would be manageable, but the wrong shade of red, purple, green, or blue (wihch, when seperating systems by colour, would inevitably get used) would be shitty to work on