I have a Dufour 365Gl as well and wanted to replace some parts of the grey stripe but in the end did not go ahead for various reasons. I found https://www.thegraphicsboat.co.uk/ were very helpful and would for example cut a 45mm stock strip down to 43mm which was what I measured for the grey stripe. They sent me their “standard” light grey and silver. One was close but not perfect but I suspect what is on the boat has faded very very slightly. I cannot recall which it was but will see if I can find the sample and measure the other stripe tomorrow but there is always the risk they might be different!
As for temperature, we were polishing the boat last week when it was around 8degC and http://www.generationgraphics.co.uk was applying stripes to the boat next to us. We took their details as they said they could match our stripes but not before our relaunch.