@Margaret
I visited the old DDR twice before 1989 - it wasn't just the schools which were grey, but the whole country. Schools reflect the society of the country where they are situated. In the case of the DDR, I don't suppose the pupils had much to aspire towards. I also visited a 'Gymnasium' in the former DDR (Jena) in the 1990s. The building was still grey and I can't honestly say the pupils were grasping the opportunities they were being given, which I suspect was to do with the society in which they and their parents had been raised.
I have a lot of time for the German 'Realschulen', but the UK never had technical high schools in all areas, although this was intended in the 1944 Act.
I'll put my hard hat on here. If I had a magic wand, I'd have selection at 15 in the UK (having abolished GCSEs, which are no longer necessary) and allow pupils to decide, in consultation with parents and teachers, their pathway for the last three years of compulsory education. They would be old enough to decide and would have had a chance to try all subjects in the first years of secondary education, so would be able to make decisions based on experience. Most importantly, they wouldn't sit a flawed exam at the age of 10/11. Big all-ability comprehensives, such as the one my children attended, already do this within the same building.