RGB histogram??

Hi all,

I want to analyze a series of digital photos to see what colors appear
most frequently. Assume all photos are in 24 bit RGB. Do you have any
idea how to do it?  Just generate a 255 x255 x255 table, each entry of
which contrains the number of times that color appears?

I think that this analysis is very common and useful. I guess someone
should have done it before.  I don't find any information about this
in literature, though. Do you know if there is another method better
than the 3-D table above? and it would be great if we can visualize as
the case of 2-D histogram.

And do you know if there is any paper which discuss what colors are
the most common?

Thank you.