When using a Rambam string which is part blue and part white, how should I align the color change in the talit hole? From the pictures on your site, it seems that you had the part where it changes from white to blue (speckled) going into the hole and full blue coming out. Is this correct?
Correct. When using the Rambam string set (regardless of which method you choose to tie) the shamash string should be placed in the hole such that one side of the begged has tekhelet and the other side has white. This is of course in the ideal, however due to the way the 8 strands of one tzitzit cord are twisted together there will be an area (as opposed to an exact line) where the color change occurs. As such you should try to place it such that one side is fully blue and the other side transitioning to white; however, I like to make sure that the white side is all white by the time the string is used in the first knot. This because the Rambam himself required that the core strings should be all white – so technically, he would be satisfied that there is no blue in the core, but I like to be conservative.
– Mois Navon