Change a TreeGrid row number field's background color

[pwilliams]

We are using SmartClient LGPL v. 11.1 in IE11.

The TreeGrid has the option to show row numbers. Is there a way to change the background color of an individually specified row number cell? We are using getCellCSSText to set the background color of cells, but a row number cell does not make the call. I tried to have a field before the tree field, but it appears that any field marked treeField will be the first field.

[Isomorphic]

Row number fields do indeed call getCellCSSText(), we just double-checked.