Tyson doesn’t have dreams anywhere near as much as he does nightmares.
The dreams that Tyson does end up having are usually less coherent than his nightmares, fragments of figments rather than the linear - and horrifying - narrative of his nightmares.
Usually Tyson has an easier time trying to remember the sensations of the dream, rather than the events that happened: feeling warm and safe in arms that could only have been Sebastian’s, grass tickling his back and the scent of Kim’s coconut shampoo, or the steady pressure of James perched on his shoulders and the taste of sea spray against his lips.
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.