Can you be more clear on what you want to edit?
If you look in /styles/colors.css the comments explain what edits what.
The rows are:
/* row highlighting on hover */
.tgrid tr td { background-color: #FFFFDD; }
/* Alt rows used on most data tables */
.row1 { background-color: #F4FAFF; }
.row2 { background-color: #FFFFFF; }
/* auto-highlight */
.row1.highlight td,.row2.highlight td {
background-color: #FFFFDD;
}