"Neutral" as I see it usually means not "transparent" nor greatly colored.
D&R has always seemed to have this "neutral" thing going for them. Their design-focus seems to be on feature-heavy mid-size consoles and trying to keep the signal intergrity intact as much as possible at the same time (considering it has SO many features compacted-together in a fairly small space, though it is a mid-size console), all while still keeping "budget minded". The result is "neutral", unlike something such as an SSL where signal intergrity is greatly compromised for the insane amount of features!
Is the guy coming out of ProTools for mixing? That's pretty common when you're working on a high-quality.