yellowing on scanned negatives

[Methias]

Hello all,
Recently I got my hands on 40+ years of family color slides and negatives so I decided to digitize them all.
I picked up an Epson 600 scanner and went to work. Things went well until I got to some 35 year old negatives stored up high in a closet that adjoins the attic and an exterior wall. Some of the negatives have a purple appearance and when scanned are yellow hued.

Others have little yellow spots everywhere.

My 2012 Mac has Iphoto and I can use retouch for the dots but Iphoto can do nothing for the yellow hue.
I downloaded Gimp to try and correct what can be corrected but I'm not getting very far. Gimp is a powerful program but as a newby user I am a bit over my head here.
Can anyone (who knows the Gimp software) help please?
Thank you for your time.

 

[compur]

Try adjusting color balance by bringing up blue and reducing red and green.

 

[Pixeldawg1]

The opposite of Purple in the color wheel is yellow, so it makes sense that your NEGATIVE with purple hues, would be a POSITIVE yellow. You should be able to do some color adjustments prior to scanning or correct this in Photoshop. It would be better to make this correction in the pre-scan by incorporating the proper colors in to neutralize the yellow. Something else you can do is place this image into Photoshop, go to FILTERS>CAMERA RAW FILTER and within that filter, at the top, go to HSL Adjustments and take the yellow away. Now, this will make the image more monochrome, which you could either give a sepia tone tint to make it look more aged, or hand-tint it to taste.

 

[Methias]

The opposite of Purple in the color wheel is yellow, so it makes sense that your NEGATIVE with purple hues, would be a POSITIVE yellow. You should be able to do some color adjustments prior to scanning or correct this in Photoshop. It would be better to make this correction in the pre-scan by incorporating the proper colors in to neutralize the yellow. Something else you can do is place this image into Photoshop, go to FILTERS>CAMERA RAW FILTER and within that filter, at the top, go to HSL Adjustments and take the yellow away. Now, this will make the image more monochrome, which you could either give a sepia tone tint to make it look more aged, or hand-tint it to taste.

First off, thank you for your input on both pre and post scan work.
Let's see if I understand,,,
If I place a yellow filter over or under the negative and scan again, that could cancel out the purple / yellowing of the scan. As luck would have it, I just happen to have a 1 inch thick booklet with dozens of filter samples.
I'm going to give that a shot and see what I can get.
Again thank you.
However,,,,
Since I have already scanned all the negs from this batch I would like to know how to correct the problem with the Gimp software that I have already.
I don't have photoshop, that's a bit beyond my budget right now.
I do however have Gimp. From what I've been reading Gimp should have a similar ability but as a neophyte, I'm virtually clueless.

Does anyone else here know Gimp?

 

[Methias]

Try adjusting color balance by bringing up blue and reducing red and green.

I've been fiddling with Gimp to try to do just that but I'm missing something. I think masks might be the key here, and I've read the tutorials, but my head is still spinning trying to figure it all out.

I'm really hoping for someone proficient in Gimp to jump in to help.

Till then, I'm going to keep playing with it and hope for the best.

Thank you for your input.