The RowNumber method only works with a group of parts, that is, with a lower-level group (without specific group columns). Think of it as returning a row in a dataset.
Instead, I would write an expression that computes the equivalent of RowNumber, but for the group level - as a rule, something uses RunningValue ... CountDistinct in the Group Key field, for example:
= Iif ( RunningValue ( Fields!tableid.Value , CountDistinct , "TheNameOfYourGroup") Mod 2 = 0, "White", "WhiteSmoke")
Mike honey
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