Thank you Breck and very interesting. I have never seen such striking contrast between the 2 rods used to fabricate the tubes (Dean is correct) and I can't imagine that the contrast was not purposeful.
This is Parker D3 (3 Iron) which clearly shows that the "scroll" is composed of the edges of adjacent rods, with a wavy "zipper" weld between, the 'stars' are from the same twisted rod, and that the ribband edge weld is straight
SO Breck's pattern has one rod staining more darkly alternating with one rod staining less so.
E. Heuse-Lemoine of Liege said in 1884 that the pattern coloring and contrast was dependent on the source of the coal, the source of the iron, and whether charcoal, coke or coal was used by the smelter. I suspect, but it is only a guess, that the tube makers chose rods which colored differently, and used one of each simply for the aesthetic contrast.