There are references here, but I think the color is yellow for 54-57 engines and green for 58-62 engines. The 58-62 MAY be full flow oil system, depending on the position of the dowel pin just above the lower oil port in the block. If the pin is pushed into the bloch, it is full flow. If the pin is flush, it is a by-pass system. Mine is an April '63 block (D3 3), but has a by-pass iol system. Propbably because it was a replacement engine in a '55 school bus.
Joe D.
