The easy way (in the sense that you only need to use Matlab and a bit of HTML) is to add HTML tags in the cell contents, as shown by Walter above. This is easily done by adding the '<html>' prefix to the cell contents (as a string, not a numeric value), and then adding tags such as <b> (bold) or <i> (italic) or <font color="red"> (for color).
The more complex way (but faster and one that does not modify the table data) is to use a CellRenderer for the specific table column, that would highlight the cell contents based on its run-time value. I explained a real-world usage example here: http://undocumentedmatlab.com/blog/uitable-cell-colors
You can find out a lot more above both of these alternatives and other uitable customizations in my uitable customization report and my book Undocumented Secrets of Matlab-Java Programming
