Through extreme pain, the effects of strong painkillers, his own recreational use of drugs, Jim’s experiments, fever, and exposure to extreme heat, Tyson has ended up hallucinating many times.
That in and of itself doesn’t mean much, but the way it interacts with his Synesthesia becomes tricky. His form of Synesthesia projects over everything he sees, including his memories.
Whatever is a part of Tyson’s reality can become covered in maps, provided he can construct a mental map or blueprint of it. A single sheet of paper, unless depicting a sketch or photo of something his Synesthesia would normally colour, won’t be of any interest.
When it comes to hallucinations, his Synesthesia gets very confused. The effect varies depending on what is causing him to hallucinate and how strongly it is affecting him. Sometimes his vision becomes unbearably colourful and messy, layering over his actual vision as well as the images his mind has created.
Overtimes, his hallucinations will be the only things coloured as he locks the real world away complete, and sometimes his hallucinations will lack additional images from his Synesthesia, whilst the real world still appears in the background with those images.
The only eventuality that never happens is that his Synesthesia colours nothing with maps. Tyson can suppress his Synesthesia, push it away into the back of his mind and focus on the real vision his eyes provide, but he can’t make it go away. It’s the equivalent of training yourself to tune out roadworks or banging as white noise. It’s still there, just distant and not given conscious acknowledgement.
Dreams are varied, though more consistent. If it’s a memory, the colours and maps remain as they were; with some allowance for changes in his emotional response if the memory is adapted whilst he dreams. If it isn’t a memory, then only things that Tyson does remember will get coloured.
For example, if he dreamt that he was walking through a fake building with Jethro, then the building would appear in its ‘natural’ state, whilst his brother would get his normal colour palette.