By definition, anything with a coil of wire will color the sound because inductance will cause a resonance frequency spike somewhere. So...by "neutral" do you mean a pickup with a frequency spike that is above what are usually considered bass and overtone frequencies, say, 5 to 7 kilohertz and up; or by "neutral" do you mean something akin to "traditional" tonal palettes of the traditional pickups, just not as spikey a peak; or by "neutral" do you mean something that does not have the treble rolled off, as some of the above posts have described; or do you mean something else entirely different? For example, because a DiMarzio Model J pickup has a bit of a mid dip but an extended top end, some people refer to them as sounding "hi-fi." I prefer my EMG 40CS soapbar, because the mids are not boosted, the bass has presence, and the top end to my ears is "neutral," neither boosted or rolled off. Bartolini CSC, or "Classic" series pickups have a little bit of upper mid presence to slot the mix, but are not obtrusive. So there are many flavors of what people consider "neutral." Or do you just mean that you don't want the mid thump of a P-bass pickup or the upper mid growl of a typical J-pickup?