The request did not specify the use to which the Munsell charts were to
be put.  Munsell charts are a very useful, if flawed, means of making
observations about soil colors.  I always have excavators specify soil
conditions (wet, dry, etc.) and anything else that might be relevant,
make multiple observations, and so forth.  It is like any other means of
making regular, systematic, and controlled observations, especially in
situations involving multiple observers.  Like passing all deposits
through screens to have a control on recovery by knowing everything has
been given equal treatment.
 
This said, I have always thought it rather silly to use Munsell
designations for colors of fired clays and glazes.  The color names and
hue designations were developed
for soils and cannot begin to accommodate the range of colors that
occur in pottery and ceramics.  But I would never dismiss out of hand
anyone's attempt to make systematic and replicable observations of
physical characteristics of materials.  What's really needed is a
combination of objective and subjective (etic and emic) approaches to
measuring and describing things.
 
True, Munsell charts are expensive, but you can always buy only the pages
that are most apposite for soil types in your area.  I have two Munsell
books so there's always one handy in the field.  Wouldn't be without them!
 
Can I get some of that seaweed green to redecorate my bathroom?
 
M.Beaudry