Színes kondenz ügyben konzultáltam egyet közben egy szakembernek látszó (a contrailscience szerkesztõjével) jóemberrel:

The "Engine exhaust characteristic" is mostly how much water is in the exhaust, which determines how much condensation there is, and how thick the trail is. If the trail is too thick, then you will not be able to see through it, and the bands of color will be too faint to see. Also in the mix is the amount of particulate matter, which governs nucleation. The speed of the jet relative to the engine power is a factor - when climbing, the power is high, but the speed is low, so more volume per meter is emitted. There is a different situation when cruising or descending.

This may also tie into what you see with the colored stripes that seem to be centered on the plane. The consistency of the contrail varies between the plane and a distance of some hundreds of meters behind it, as the water vapor takes some seconds to condense and ultimately freeze. At the various stages of this condensing and freezing, the refractive and reflective properties will vary, which may lead to a banding based on this variance. See this photo:

Link

The colors vary along the contrail as the optical properties of the trail vary as the exhaust water condenses and freezes. It is not the same as a halo that is centered on the plane. It think this is what is happening in your photo - notice the colored portion is during the section of the contrail where the width is spreading out - meaning the exhaust is still condensing. Where the width is constant, there are no bands.