What do you think of doing "spot color" sometime, maybe as a monthly theme, maybe as a subset of monochrome, maybe something else?

I'm thinking of the photo I took of my son with his little boy in a field of pumpkins, and I made the basic picture B&W but had the pumpkin my grandson was holding as orange. Also, Reg photographed a line of dancers at a Renaissance Fair, with most of the picture B&W, but one girl in a dress of many bright colors whirling around--not a single "spot color" but the same technique or theme.

Any thoughts? Suggestions, or guidelines? I'd be interested to know what everyone thinks.

   -- Jean