It is a load of bollocks, "change everything yellow", can't believe anyone is stupid enough to listen to this crap, let alone believe it.
Blues are defintitely NOT THE SAME AS YELLOWS the flow rate is totally different.
Yellows will flow to around 285, blues to around 390.
This is assuming a DC of around 85/90%.
The blues came in due to a software change in the ecu used on the cars so fitted with them, and is probably more to do with ford getting a bulk deal on these particular ones.
tabetha