No matter how it's done, the problem is we have a lot of skins and vanity shields with different colors of warp nacelles, bussard collectors, and impulse vents. That "glow" is on such a high layer it even overrides certain vanity shields. It's a similar but reverse problem with the Legendary Gal-X. The Mirror hull markings…
There is too many of them FAR too many of them. Giving us a slider to adjust to adjust the opacity of all space and ground effect is the best solution.
Put a shield around where the Rex spawns that only drops 1 minute after the BZ is set to full control and the rex does not spawn till that shield drops. Easy.