Is disk version of iWork 08 compatible with El Capitan Opened a iWork 08 Pages file created in 2015 and very little appears.  All text is white and can’t be changed to black. This was not a problem on my previous OS.  IS this a El Capitan issue?
If you have installed iWork from disc you may be able to then upgrade to the latest version via the App Store. It's been a while since I tried it but it worked a few years ago.

That would then give you a compatible version that can open the older files.