How would I automatically color the area between two lines?

Using an Area charts either leaves the lower area without gridlines. Using stacked area charts uses the wrong data(sums the two lines).

You need two more columns. Suppose that your data is in Columns A and B (with headers in A1 and B1). Then in C1 put Area1, and in C2 put

= A2

and copy down. Then in D1 put Area2, and in D2 put

=B2-A2

and copy down.

Then add these two series to your chart, you need to hide Area1. You need to access Format Data Series dialog box, select Patterns tab, and set Border and Area to None.

Adjust your colors appropriately.

Is this what you had in mind?

I've tried your approach. When you clear the area you either lose the grid lines or the area of the reamining chart covers to the axis.

I've also tried coloring the grid lines so that there are no gridllines at all. I didn't like the presentation that way.

thnx for your suggestion.