My (very) naive take:
Was it important part of the game that the store looks just like IKEA?
If yes, that probably makes it more likely that it was a trademark infringement and that IKEA was justified. If no, it shouldn't be a big deal to change the colors, just to avoid potential confusion.
Yes it unfortunately was. Because the SCP lore this game recreates refers to a horror scenario set inside an infinite inescapable ikea store.
I saw beads at a bead store today that were clearly Pepsi/Sprite but they were "Pepsis" and "Spritc", presumably to be legally distinct.
Is it important that the beads looked like Pepsi/Sprite? Kind of, people want recognizable brands