if I place the 2020 easter heads do they lose their coloured tag?

 

Yes. You place any unplaced heads aka with colored names and lores, they'll become in white without a lore.

 

Placed heads immediately lose 70 to 80% of their value. It will just say "Head" in white

 

When you place a head, the lore is removed, the lore being the coloured name and the text below. It'll just be automatically named "head" or if it was taken from an actual skin then it will say "x's head". Placing heads is not ideal if you're wanting to sell it in the future, i.e if you just want them on your island for the aesthetic forever, then go ahead and place it but don't expect much money if you do want to sell it in the future!

If I were you, I would just put them in an item-frame and just make sure that the setting is disabled in /settings so players can't take it out, and make sure you untrust anyone you do not know or anyone you wouldn't trust having your head around.

Hope this helps!