So, you want a highlight for each order, not each line?  For that I set up something like:

If (condition) then 1 else 0

...and then do a sum(formulafield,groupfield) > 0 to use it...

I am not looking at your report or even the standard one so i could be wrong.

isn't this a master/detail report with the items appearing on a subreport?

if so, you might have to pass values from subreport to main.  Alternatively, do the highlighting on the subreport

Yes just trying to highlight a header field on each order based on the line values.

Attempted with this but keep getting the error, which I assume because my condition is all wrong.

IF ({SO_PickingSheetWrk.ItemType}="1" and {SO_PickingSheetWrk.UDF_QTY_PULLED}<>0) then 1 else 0
IF SUM({@qty_pulled},{SO_PickingSheetWrk.GroupField}>0 crYellow else crNoColor

What error?

Created this formula "Detail_1_0"

IF {SO_PickingSheetWrk.ItemType}="1" and {@udf_qty_pulled}>0 then 1 ELSE 0

Then added this conditional format to the barcode header

IF SUM({@Detail_1_0})>0 then 
    crYellow 
else 
    crNoColor

You'll want to change your sum to be by SO (using an appropriate report group for that), in case you print multiple picking sheets at once.

I am not sure I understand how to do that.

Sum ({@Detail_1_0}, {SO_PickingSheetWrk.SalesOrderNo})

Without the grouping designation in the sum, it is a report total. 

• Printing one SO at a time, a report total is no problem. 
• Printing more than one SO, using a report total, the format would be applied if any of the SO being printed satisfied your condition.