Problems with stacked bar charts - but not others in same workbook
 

A coworker put together a work book for reporting. All I have to do is enter
figures in 3 or 4 fields on one sheet and the bar chart is supposed to pop up
on the second sheet. We are tracking several programs and each program has a
data input page and then the "pretty" chart page. On some of the charts,
they come out just fine. But there are 2 (and 1/2 of a 3rd - it's only a
little bit wrong) charts that are showing the total amount in 1 color instead
of the 3-4 colors that it should be showing.
I would like to think that I am exceedingly proficient in Excel (and, truth
be told, I don't think said coworker *really* knows what they're doing ...),
but I have never seen a problem like this.
I have been all over it, ever which way I can think of, but I have no idea
how to fix it.
Any ideas?
TIA!