Hi, I checked with the devs and this is because we try to match the Corona color space to what is selected in 3ds Max, and if no match is found, we fall back to sRGB. I understand that you would still like to be able to override it. We will see if this can be done. This is now logged as (Report ID=CMAX-1659).
Meanwhile, I think you can hack it by running this script renderers.current.colorSpace = 2
No idea if it works as expected though.