Control of fold separator color

I can’t seem to find a way to change the line thickness or color of the fold separator which appears when code is collapsed into a fold.

I’m using an XML format in an Emacs ‘orgmode’ style, so I’m trying to make the fully folded presentation easy on the eye. Currently it’s hard to scan the text with very high contrast (white) irregularly-spaced (only some leaves have hidden children) lines scattered through the text. Ideally I would bring it down to a much more subtle grey.

Does anyone know if this is controllable and which part of the editor configuration I need to look at. Thanks for any help.

Here’s a screenshot of the problem.

Looking through the structure of several color scheme files, I don’t see anything that would appear to be directly relevant to either the color or thickness of the fold indicator. Being able to specify the color, in particular, would seem a logical (and welcome) addition to the color scheme. At present, I think we are limited to turning it on/off in the preferences under “Smart Editing”.

I logged an enhancement request for this [] as I think it is a good idea and I would definitely take advantage of the capability in my own color schemes.

There is no setting to configure it. It based on your Foreground color.