These endothelial cells are anchored to structures in the interstitial space by collagen filaments, which allows the lymphatic capillaries to remain flexible but retain their overall shape.
It's an expanding cloud of gas and dust, the remains of that dying star, and the colours are different chemical elements, so the orange is hydrogen, the red is nitrogen and those filaments of green are oxygen.
In 1880 Edison discovered the right material for his lightbulb's filament: carbonized bamboo fiber, which burned longer than any other material yet tested.