As a novice in my first year of comp shooting I found some of the Wendover targets difficult to see. my problem was that the white backplate seemed to merge into the background in backlit situations.
On reducers if the paint has been shot off the paddle, and a number of shots have hit the hole surround, it becomes impossible to distinguish between the two.
This of course is not a problem if you are confronted by a nice, new, freshly painted target!
On balance I am much more comfortable shooting a yellow black colour scheme.
Targets seem much easier to acquire (through my budget/mid-range MTC Viper 10x44 scope) using these colours.
p.s. This is NOT a criticism of the Wendover course, I REALLY enjoyed shooting there.