Possibly caused by the fix for MC-164163 and may be related to MC-166397.
How to reproduce
/team add red
/team modify red color red
summon minecraft:magma_cube ~ ~ ~ {Team: red, Glowing: true, ActiveEffects: [{Id: 14b, Amplifier: 0b, Duration: 500, Ambient: true, ShowParticles:0b}]}
→ ❌ Notice how the mob is outlined in red for a split second before it becomes invisible and turns pure white
Confirmed for me on 1.15 pre-6. The entity appears pure white from some angles, and glows with a white outline from others. Entities which are visible work as normal, and those on the same team as the player with seeFriendlyInvisibles set to true work properly as well, as depicted in the second screenshot.
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