I now have The Sims 2 Ultimate Collection and this means that I'd have all EPs and SPs. This is important to take in account, if I share Maxis recolours and furnished lots.
If you still got the old version of the Sims 2 with EPs, SPs, all should work fine but if you haven't got some Maxis items from EPs or SPs not installed, some Maxis objects will simply not show up for you at all on a lot. For wall papers, floors, terrain paints, they're always added normally and showing up.
Thank you for your attention.