Alfa 75 which coolant sensor

[Alfamania]

Hi all, I need to most likely change my coolant temp sensor on my Alfa 75 3litre v6. Reason for asking is that currently I have a blue plug one on there. From what I am hearing apparently The correct one is the white coloured one Is this true? My 75 is Bosch L-jet, if anyone can advise would be gretly appreciated, thank you