Green means the room found your drawing. Red is the exact filename it looked for and didn't get — rename your file to that, or tell me what you called it.
Same idea, for sound. If a part shows red, the room never got a file for it — a name that doesn't match, or it isn't uploaded next to the others. bass / guitar / drums play as soon as someone's at their amp. synth / noodle / scribble only play once somebody is actually SITTING on the sofa — press 4 to cycle who's there, or wait for the room to seat someone on its own. No sound at all from a part that shows green here usually means nobody's in that spot yet, not a broken file.