Just reuse the skyrim ones, jeez, no need to make it 10x too hard.
we can colour match the skyrim ones, and change the colour effects if we need.
Or just lose the light idea. I don't like it. First, this puzzle is mechanical, and in no way magical. It's not got any special properties or powers besides the ability to turn it into a key by solving a puzzle. Secondly, we don't want it to be too eye - catchy. It's supposed to be hard to find.
The only thing which matters to me it is notice this cube. What I understand in term hard to find is that u have to search all rooms. The frustrating part could be if u skip it and then u will waste time. So maybe fancy disco light it is not so necessary to implement but I think it only needs to be putted on sth bright (maybe just piece of paper). And that's all.
Oh, but frustration from missing it is totally what we should be going for. This is Morrowind, Morrowind makes sense and doesn't add unnecessary stuff just so that players with small attention span don't break into angry tears. Morrowind was all about rewarding you for searching every damn corner for items that are really hard to spot, just remember how easily you could skip fists of Randagulf for example.