Great technical answer from Spikey. I’ll have to remember that myself.
I would say that, while the blue is off-putting in my experience as well, it usually tends to diminish naturally as you add skin textures and adjust the RGB radii. If the blue is still present at the end of the lighting + shading then I would focus on the SSS settings to get rid of it.
Most of the time the the blue crops up for me when the RGB radii are too far apart from each other (ex R=1, G=0.3, B=0.1). The closer I push all the values toward 1 the less blue tint (ex R=1, G=0.6, B=0.3). But the cost there is also losing some of the redish-orange scatter tint. Keep in mind you can also use masking to do this in only problematic areas, the eyes of which are common.
