It's been so long since I've posted an update that the thread I opened was archived. But following GGJ I've been inspired to pick this project back up. I've made good progress. Instead of making my own art, I've leaned on OpenGameArt.org to source placeholder tilesets etc until the day I hopefully am able to allocate more time to making art or hiring an artist.
I've also changed the way the B&W works, instead of it being B&W assets, it is a camera effect which will be important for narrative reasons.
I've created an inventory system and a load of prefabs/scripts for object interaction, I have pretty much all the assets needed to focus on map building now so hopefully I use this momentum to make this an actual game!
Let's hope the next update isn't too far away.
Cheers for reading!
Edit:
Here is the previous thread: https://itch.io/t/2228138/spectrum-a-story-about-colours#post-640783
And here is the OpenGameArt tileset I'm using as a placeholder: https://opengameart.org/content/zelda-like-tilesets-and-sprites