Thank you for tip!
Unfortunately, that didn't work: I've cancelled the game's folder, and erased the LiminalDreams one in the AppData subfolder, in order to do a clean install. I've made through all the worlds in order, discovering all secrets, and after I got the TRAVEL button I flipped the switches in the order shown in the video (green, purple, yellow, orange), but it didn't work: still, yellow and orange are the only squares lit up.
I'll add a screenshot of my progress:
If only there was a way to contact the developer about this...