It's not the colours, it's the consistancy. I've recently had pots as thick as jam and have just been using matt varnish aerosols which gum up before they are half empty. These aren't old batches working through the system, this is UK manufactured rubbish.
British isn't best just because it was made on these shores. It's only best when it really is the best. That's why we lost both a motorcycle and car industry, we were convinced that foreigners could do no better than us so we stopped trying.
One day, the blinkers will come off and we'll start working towards being best again.
Of course, if the British people didn't prefer low cost to quality, this would be a lot quicker.