I have an XY scatter plot of temperature inside an office building throughout
different times of day across a 3 week period. What I would like to see are
coloured bars that highlight when the office is open (operating hours).

I tried adding colour-filled rectangles with 50% transparency, but I am
having printing issues. It looks fine on screen, but when I go to print the
bars are scaled differently than the chart thus they don't line up properly.
I think this might be a bug in Excel. This issue comes and goes; sometimes it
prints OK, most of the time it doesn't (and I haven't changed any settings!)

Is there a better way to do this? I must admit, using the coloured-bars is
very tedious. If there is a more elegant way to colour-code the chart then I
am all for it!

Thanks,

Rebecca