Hi,

You could format each segment of the line.
Select the series and then use the Right cursor to move through the
segments. Note if you only have 1 series changing a section of the series
will cause the legend to report each segment.

The other way is to use multiple series. But it does depend on where along
the line the colour change occurs.
Leave cells blank when you do not require the line for a particular colour.

This example uses an xy-scatter as the line changes colour between
categories.
http://www.andypope.info/charts/conditionalline.htm

Cheers
Andy

--

Andy Pope, Microsoft MVP - Excel
http://www.andypope.info
"biff" wrote in message
...
How could you change the color of a line in a line chart so that at some
point on the graph the line changes color?

Say like the line chart shows data over the months of a year but at month
July, the line on the chart changes from blue to green and is green the
rest
of the months.

I am asking about 1 line being two colors.