Black error bars don't show up on black lines in Graph Builder

[#1]

I'm prepping a figure for manuscript publication and one of the editors is requesting a lot of minor edits in font size, color, marker size, etc.

For the error bars I have created for all of my marker points, for some reason, when I select the black color box the error bars disappear. For this screenshot here I have actually selected the darkest gray possible. When I select any other color, it seems to work just as it should. It's not overtly noticeable that it's actually a shade of gray instead of black but it becomes more evident when the image is blown up. Is there some sort of glitch or some reason why strictly "black" error bars don't show up on black lines? Any ideas on how I can fix this?

[#2]

I've had the same problem. Specifying "Black" or 0 in the line color in the script didn't seem to help.   My solution was to add a crayon color (lead) from customize window.  That adds the following line to the script

DispatchSeg( BarSeg( 2 ), {Line Color( {25, 25, 25} )} )}

which seems to be an RGB Code. However, I think 0,0,0 would be black in RGB and that gives the grey color.  I tried replacing the 25,25,25 with 1,1,1, but it really doesn't make much difference.  They both look black to me.