Add a text box to the report, and set these properties:
Control Source =1
Running Sum Over All
Visible No
Name txtCount
Format General Number
Add a text box the size of the Detail section, behind the others (Format |
Send To Back). Then choose Conditional Formatting on the Format menu, and
set Condition 1 to:
Expression: (([txtCount] - 1) Mod 6) < 3
and choose the grey in the bucket.
The running sum accumulates 1 for each record.
Mod gives the remainder after division.
If the remainder is 0, 1, or 2, the expression is true, so the text box is
grey.