Agromyzidae seem to be more or less black so my second guess is Lauxanidae, but again the color makes me hesitate.
The 3 mm fly is from October, near Eys.
Probably Phytomyza ranunculi, a very common and very variable species. The summer form is very pale like this while specimens developing in cold weather are much darker and closer to 'normal' colour range for Agromyzids.