Military hair sporran strap colour?

[MenOfTheNorth]

As promised (threatened) in my welcome post from yesterday, I arrive here on the forum as someone new to kilts and with a multitude of questions. I have been spending some time using the search feature on the forum to answer some questions - and the knowledge possessed and shared here is terrific thank you - but I still have some questions. I'll scatter them around the various sub-forums with which they seem to align. Please forgive me if I mis-name/identify anything and I welcome corrections. I'm keen to learn.

I am curious about the correct/appropriate colour for the leather strap for a military hair sporran. I have only seen original WD-marked ones in white/buff, no other colours. Were brown or black straps used? Was it dependent on the regiment? Photos and links to any sources of black-coloured examples welcomed.

Thank you.

MOTN