Strange, the ones I picked up in Wickes last week are blue. For food? in Wickes? hmm
+
trousers were a game changer
Either waterproof trousers, or roubaix bib-longs with grip-grab gaiters.
The only thing keeping your feet warm is the blood flowing to them, so you need to keep your legs warm so the blood vessels stay open and let as much blood flow as possible. As soon as any part of your lower body starts to get even a little chilly it’s game over as it’s response is to limit the onwards blood supply to preserve core temperature.
And if you’re not using gaiters with any boots then water will obviously just get in the top.
Cleaning and re-proofing the boots does help as well.