It is possible, but the solution depends on one or two things. Suppose
you're looking for the word "blue": will the cells in question contain
*just* the word blue, or might it be contained in a text string such as
"the sky is blue"? Do you want to count a handful of words, and if
yes, do you mind counting one at a time or do you need to count them
all at once (for instance, count red, white, and blue in separate
formulas, or all in one formula)?