The neighbour's very large one produces yellowy foliage in the autumn. I wasn't aware they were meant to orange red.

The RHS site suggests the ayutumn colour is green.
link below

https://www.rhs.org.uk/plants/details?plantid=778

Well I live in the Northeast US and I can tell you Autumn color is very directly tied to the environment. There is nothing wrong with your plant it's all about the sunlight fading temperature precipitation cool nights and the previous summer. That all affects Autumn color or the lack thereof.

yes that is true but not all plants put on a really colourful show of reds and oranges and Exochorda is one of them that gives a soft yellow autumn colour.

Thank you for the reply’s however my plant doesn’t give any colour in the Autumn or after flowering , it just eventually looses its leaves ,but flowers again in the spring as usual ( with many compliments )

OK not all varieties of Exochorda gives fall color. From the little research I've done, only The Bride Pearlbush will give a soft yellow autumn color. You must have one of the others.