Lovely shot, Huw. It looks like the same species we get in Korea. Certainly not too bright for my taste; I love bright colors. I can also see a crop in from the right to remove the brown things there, as the petals are already cropped in. Hoverflies can be very obliging subjects and seem to love bright colors too!
Huw, the colors are very nicely eye catching and, as your close-up shows, the details in the eyes are outstanding. If you have more flower below, I could see rotating this maybe 20º clockwise and moving the hoverfly off center.