I would agree with you, but archeologists often classify finds as "for ritual purposes" without any proof or evidence that it was used in a ritual, without specifying what ritual is involved, or how the find would be used in the ritual.

Likewise archeologists will classify finds as tools when they don't have nearly enough knowledge about the craft in question to be able to do this properly (see the extensive mis-classification of weaving swords/beaters as weapons [0], but there are many other cases).

So I'm a little reluctant to cut them some slack and say "this is how scholarship" works when they get all petulant about including colours that we know the ancients had, in ways we know they used them, for this kind of reconstruction.

[0] https://www.academia.edu/67863215/Weapon_or_Weaving_Swords_a...