A non-neutral-grey object disturb a Munsell N5 wall

Hi guys,
I have a wall painted with Munsell N5 for color grading.
Unfortunately, a big cylindrical bass-trap will be placed near the reference-TV, on the left. It's a ø43 x h104 cm cylinder so it will enter peripherally in my field of view.
The problem is the grey: its grey is obviously non-neutral, so it can “disturb” the perception of the neutral gray on the wall.

Anyway I can choose the luminosity of the fabric: from white to grey to black.

My question is: which level of luminosity could attenuate the conflict with the Munsell N5? Should I choose a fabric that is as dark as possible? Or as white as possible?

Thanks in advance.

[Peter Chamberlain]

I would use a black bass trap but mount in front a acoustically neutral cloth, on a frame, that’s painted the same Munsell N5 grey.

Thanks Peter!