Hi,

You can not colour an individual gridline.

But here are some examples of how to add a datum line to your chart.

http://www.andypope.info/charts/averageline.htm
http://peltiertech.com/Excel/Charts/AddLine.html
http://tushar-mehta.com/excel/charts...nes/index.html
http://processtrends.com/pg_charts_horizontal_line.htm

Cheers
Andy

Jim Moberg wrote:
Is it possible to change the color of just one axis line on a chart? It
would be nice because then we could mark in red which would allow us to see
target values we are shooting for and then see how the actual results measure
up.

--

Andy Pope, Microsoft MVP - Excel
http://www.andypope.info