using v3.3.10, a banner's base color turns black whenever someone relogs with it in their inventory. here's a "before and after" screenshot: https://i.imgur.com/0GUY4rr.jpg

i am only like 90% sure this is caused by MultiInv because i don't run a server myself. it doesn't seem to happen if the player just switches worlds/inventories and back, but it still does even if they relog while their banner isn't in their current world's inventory

after further testing, it also only seems to happen if the banner has been named or patterned