Thank you, I personally want the markings to stay. I think they are cool looking.They are inaccurately called 'Stress Marks'. It is just part of their markings, not all have them or at least not as visible. As with their other makings & coloring, they will lighten & darken when affected by many things, such as, but not limited to, temperature, time of day, mood, lighting, stress, etc. You are partially right with the fawn analogy, they generally are not as noticeable when they are older, more visible when young. The odd ones will lighten & darken but always be visible. Because of the contrast on the light colored underside, the changes are more noticeable than the other coloring variations throughout the day.
I didn't know they really changed colors that's much