Is it off-topic to ask how to handle specular properly, particularly re strand (Hair Room) hair?

It seems that black is the popular specular colour, which doesn't make theoretical sense to me with my limited knowledge... but something like that is all that seems to work. I've tried white specular and the hair always turns gray or platinum; I've tried a later tint of the main hair colour and end up with something far away from what I want as well. (That's the case in the image here: the hair tip and root colours are set to dark brown, but the tint variation I used for specular overpowers the hair and makes it look pretty much blonde.)

Is black really the proper choice?

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Hardware: AMD Ryzen 9 3900X/MSI MAG570 Tomahawk X570/Zotac Geforce GTX 1650 Super 4GB/32GB OLOy RAM

Software: Windows 10 Professional/Poser Pro 11/Photoshop/Postworkshop 3