A device which is, I believe, simply called the "Color Identifier" is
sold by APH.

I have one and use it all the time.  I love the thing.  It may not be
accurate in the strictest sense (it does better on the violet/blue end
of the spectrum than on the red end) but it's quite acceptable when
you're mostly trying to distinguish between known items-- say between
the brown shirt and the purple one of the same make.  In

In my experience talking to other people who've used one and in
showing it to blind friends, it seems to be most useful to
those who have had some color vision at some time in their lives.  I
know congenitally blind people who use and like it, but I think some
experience with the subtlties of color, especially when it comes to
the brown/tan colors, helps in recognizing and interpretting its
mistakes quickly.

                                                   --Carla