Try this:
In the Report maintain a new column with Id, like it is an serial number , You can do this Using ROW_NUMBER() OVER (Order BY column)
And in your report select the entire Row which has values., go to Properties
And Under color , Update Black with
=Switch((Fields!RowID.Value MOD 3) = 1,"Green",(Fields!RowID.Value MOD 3) = 2,"Red",(Fields!RowID.Value MOD 3) = 0,"Blue")