I have noticed a similar effect. I have both RX100 IV and V models and the difference in the colours between cameras is quite striking, particularly unwanted magenta tones in the model V. I've tried to counter that by resetting the White Balance. I bumped up the temperature to 6000K via Menu > Camera > 5 > White Balance > C.Temp/Filter. In the same menu ...
If you look at any color wheel, you have two axes on the wheel:
To correct any color cast, this is usually enough. You can correct the main source of color shift in natural light on the temp axis (blue/yellow), and then do the fine tuning on the tint axis (magenta/green). Tint most often occurs through artificial light.
Photos (slides, film, photographic papers, etc) use layers of red/green/blue pigments in order to reproduce the colors in a scene; and when an image color shifts it is due to the different pigments fading at a different rate. In this case blue and green have faded more than red, although the red has faded some as well.
In order to fix this you have to add ...
My quick attempt at fixing it. If you have many to fix, you will need an easy fix.
Really, really old slides (1950s?) had a serious fading problem, but I don't think these are that old. The cars appear to be from the 1970s.
The top left seems to be the most faded. The slides probably weren't kept in total darkness and this corner saw the most light.
What you can do is to memorize what style you use in the camera. Then install OLYMPUS Workspace from here (you need the serial number of your camera). Open the image(s) and apply the picture style you use in your camera for those photos.
This will apply (mostly) the style of photo as it is in preview.
Definitely don't have the camera do any image correction. You want to get the unchanged original image off the camera, save a copy, and do all image correction using good software.
All image correction should be done by eye. The best software can only do some basic things. It can't really react to things like your underwater photos.
Normal pictures are ...