find all with same number, if all = 0, highlight?

Hi,

Pretty much what it says in the title.

I have invoices, some of which have 2-30 separate lines. I already have a variance column which goes to 0 when information is updated (if costs are correct)

I would like some solution to highlight when all the variances within one invoice have turned to 0 (or ideally a range of -5 to 5) so I can quickly check off the ones that are good to pay.

For example below showing column with 2 different invoice numbers in 123456 has 1 line with a variance of 10 so cannot be paid. whereas 1010 all say 0 so it's good to go - its hard to see in a BIG sheet like I have so I'd like it to be highlighted or even another column to the right with a figure in?

Invoice no	Variance
123456	0.00
123456	0.00
123456	10.00
123456	0.00
123456	0.00
1010	0.00
1010	0.00
1010	0.00