Everyone has an album or shoebox full of old family photos, some of which rock a wonky, Instagram-filter-gone-bad style color shift.
In this brief tutorial from Creative Live and Matt Kloskowski you'll learn how to quickly correct for these changes and can restore the photo to looking like new.
Matt's process is pretty straightforward:
Start by trying "Auto Color" from the Image menu. That's a good place to start and may possibly be enough of a change to make you happy.
If that didn't get you quite where you'd like to go, try adding a levels adjustment layer.
Switch from the RGB channel to the red channel. On your histogram you may notice a gap between the far left and the beginning of the graph, drag your black point over until it hits the beginning of the points on the histogram (as seen around the 2:00 mark). Do the same with the white point as needed, dragging it down to before the gap (as seen around the 2:20 mark).
Do the same for the green channel as needed as well as the blue channel.