Alternate row color *for a dimension*

[hespora]

Hi,

Situation: C10.2.2 on relational DB. I have a list report in which I want to employ alternating row shading not for each new row, but for each new value in one of the dimension columns. Something like:

Order     Line       Value
123       1           10
123       2           20
123       3           10
124       1           45
125       1           25
125       2           60
126       3           10
126       5           50
127       1           10

I know how to achieve this per row, but I don't think I ever had this particular use case. Anyone got an idea?