No i could not reproduce this bug in 1.16-rc1 with fabulous graphics on so i think it has been fixed.
This works if you use a spawn egg that spawns an armour stand
This can also happen if you shift click an item from a crafting table output and have a repeating command block clearing that item
This was fixed in a 1.16 snapshot
Confirmed on pre-4 with a GTX 1050ti
Can reproduce in 1.16-Pre2 with a GTX 1050 ti fabulous graphics
I have a GTX 1050ti Graphics card, 8gb RAM, Intel corei5 9600KF (3.7GHz) processor and Java 8
It was #FFA6A6
It can also appear white in the players hand in third person
You could try waiting a bit longer some world can take a while to load on certain devices. if that doesn't work then idk
If you did this with a command block try turning "command blocks enabled" in the world option setting
Are you sure you built the portal right?
go into options > controls > mouse settings and turn off touchscreen mode