Literally just after typing that last post and thinking about why I couldn't get anything from it and how I compose. It came to me!
So there are some blue and green bits, then a big splooge of yellow, then blue- green.
So the form will be 2 sections or types of sections. Then a big completely different bit. Then back to the 2 types of sections.
The time changing up the side of the graph means I'll change some things as it goes along within the sections. Don't know what. Harmony, chords not sure.
I'll try and have a go.