How to make the cell background of a table informative?

I wish to create a table in which the foreground is a number (abundance) but
the background is a visual representation of a ratio (shallow:deep).  In
other words, the background of each cell of the table would be two colours
or patterns set in a similar fashion to a stacked bar in a bar graph based
on a secondary parameter/vector.

The table will be extensive (15 by 30) and so I don't want to have to enter
the values for each cell manually, but rather refer to a variable.  I have
seen how to create single color backgrounds, and backgrounds of a color that
represents a category, but not a ratio.

Possible?