As far as I know they use a mix but they've used MORE synthetic media, that is white in color, on the latest One's
I figured most of the latest Purolator One's have a white synthetic media these days & the Bosch Premium has more of a blend (Yellow/Tannish) color? Maybe the Bosch has changed since I've looked at them last. Are you sure there's no difference between them?
Keep your story straight.