Slides that were shot using Ektachrome films often seem to turn reddish orange over time. I have been scanning many slides that my uncle shot back to the 1950s and my slides mainly from the 70s and 80s and have found this problem. The Kodachrome slides seemed to have held up well although sometimes have a bluish light tint.
I use a HP G4050 scanner which is reasonably priced and is a standard size flatbed scanner. It is designed to scan slides and negatives also by including a backlight in the lid. Just doing a normal scan of the slides results in images on the computer that are the same as the actual slides.
However by clicking on the edit option of each slide after the pre-scan is done (before the final scan) there are several options with one of being to restore faded colors. This removes the reddish orange tint in the slides and brings back basically the full colors in original intensity. It works on most slides. However my pictures of sunsets do not do well, but then probably it canít determine real reddish orange from the reddish orange from aging of slides.
Other scanners software sometimes includes software that will allow color restoration also. Articles on the Internet mention that Silverfast that is included with some scanners will also make corrections to the reddish orange tint using color correction and optimization.
Many of the slides I have scanned have still been in excellent shape although they are 30 to 60 years old.