Probably daft question but can you mix fuel injector types on the rail. Noticed recently 3 injectors on the rail have a green band around them (IWP109) and one as a beige band (IWP064). Had an injector replaced but that was one of the green ones

No all injectors should be the same. General they are colour coded to define how much fuel the injector is capable of injecting. You need to find out what injectors are specific to your car and make sure the correct ones are fitted.
Use the ePER link at the top of the page and enter your chassis number and try to find out which ones are the correct ones.

Thats weird tried the Eper link and the beige collared one is the one listed as correct surely can't have three incorrect injectors wonder if its an update on the green ones?

Regardless of colour, they should be matching in flow rate and corresponding to your car. Each type of injector has a different fuel flow rate so having different types will cause rough running and possibly worse. However as all car makers are constantly updating things, it could well be the these injectors flow the same rate, but ones is newer than the other hence colour difference. You need to find out what is the correct flo rate and wether these injectors match.Or to be on the safe side replace the ones that don't match.

Thanks Notorious. Makes sense too me. I'll check online and change if needed. Why do things have to be so complicated ?