rowClasses is meant to be a comma separted list that's iterated for each row. Useful for tagging rows with odd/even classes. You can't compute it for each row.
E.g. rowClasses="odd,even"
row1 -> odd
row2 -> even
row3 -> odd
..
I emulated dynamic styling of rows in a project I worked on by putting a computed styleClass on the first column. If your users have browsers that support
general sibling selector, then you can use this technique.
E.g.
column styleClass: inactive
CSS:
.inactive, .inactive ~ td { color:red; }