mark line in chart

I have a chart with y axis 80 to 100. I want to mark the line at 95 with a different color from the rest of the chart grid lines. Is this possible?

Found this Add target line to calc chart
This will work in my case with line graphs too.

Yup, that describes how to do the first method I referred too.

There are two possible ways to go about doing so. The first is to add data in the data set to have a graph at 95. Secondly, you can draw a line on your graph and colour it a different colour.
I am looking forward to learning a more eloquent method.