I lost a few when they were very young but the couple that survived have been totally neglected and are fine. One thing that confuses me. You refer to the dark green one. I take it that one is a Choisya but not a 'Sundance'?

I imagine its Choisya ternata, Sarraceniac, just not the variety 'Sundance', though I guess it could be 'Aztec Pearl', which is also plain green.
I wouldn't feed it anything before April, but what exactly is wrong with it in terms of symptoms? Any chance of a photo?

IWill try to take a pic, bamboo, I actually cut off the dead branches today. It is not an Aztec pearl, which is fine,nor a sun dance, but the original darker green shrub. BUt it is much paler now apart from the dead branches which were yellow. What would you use for a feed next month?

I'd first want to establish what's wrong with it I think - I take it that its in the ground? Does it have constricted root room in some way?
When it comes to feeding, anything with a balanced NPK, so something simple like Growmore would be fine, which has an NPK of 7-7-7.

Yes this shrub is in the ground and has to be 10 years old. The ground gets VERY WET as water runs off the fields above and I fear that is part of the problem. i dont think the roots are constricted, but I fear its just old age. I will take pics tomorrow hopefully

It might just be a result of excessive water round the roots - I'd expect these shrubs to live perfectly happily for a lot longer than ten years.