Contrast is Rooted in Value
Every color has a value. As mentioned in chapters 8, 39 and 40, the minimum contrast of a logo should not be lower than 40% and a signature’s contrast should not be lower than 60% regardless of whether it is a positive or reversed identity.
A designer who only designs an identity for a light or white background has only done half a job. Every identity should be able to be reversed out of a dark background. For these situations, an alternate corporate color may be employed to assure enough contrast.
Yellows only work well on dark backgrounds, they do not give enough contrast on light or white backgrounds. Whatever motivates a designer to break this principle will evaporate to insignificance if the identity can not be easily seen. Yellows only can be used for very simple shapes.
Adapted from Logo Design Theory: How Branding Design Really Works