Color rows in list view

I’ve hit a bit of a wall and need some direction. I have a form with 3 tab panels that contain list view forms A, B and C and a category field. Currently, the user must select a category then click a row in form A or B which creates records in form C. What I would like to do is somehow show the user what records have already been added from forms A and B for the selected category by highlighting those rows. Could this be done with the onRender event or somehow with CSS?

Thanks for the help!

If the fields may be colored by some condition you need to create an onREnder event, and depending the record and the field, or condition return one color or other to colored the entire row. With css you only can colored even or odd rows and selected.