Simmer a simple strained (like tea, or a coffee percolator) brew for a little while and it goes from yellow, through orange to brown. Simmer it longer and it gets darker, and at some point some of the brown matter congeals to a fine powder. Both the heat and the oxygen from the air contribute to changes in the colour-bearing molecules. It's not especially to do with the change of solvent.
When I've let the fresh, yellow brew sit and dry out somewhat on a white porcelain surface, gently wiping off the yellow-brown residue has often revealed a red stain. Oxygen has turned some part of the harmala material red. There are some compounds present which air fairly oxygen-sensitive when in solution.
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli