Brownish? Check. Pale veins? Check. ‘The vertex has two streaks at the anterior edge which may join in the middle’? (You can’t really see this in my photos – I had to enlarge them to find them. Also, if, like me, you aren’t familiar with the anatomy of a leafhopper, the British Bugs website has an illustrated page of bug bits.) Check. ‘And there is an orange-brown transverse band behind this’? Check. ‘The anterior of the pronotum has variably dark markings’? Check.
Six checks is a winner! This little leafhopper, a new find for me, is Speudotettix subfusculus. Look for it on trees, especially Oak trees.