I am developing an app that has multiple skins that have different branding colours. Each of these brands have their own target which, in turn, has it own asset catalogue. In these catalogues, I store the colour assets for each respective brand.

However, when I try to use these colour assets in the interface builder, I can see the list of Named Colors will all of the correct items in. But the colours that are listed are a mix and mash of all the colour assets, even though they technically belong to another target.

I have tried cleaning, restarting Xcode and rebuilding but it doesn't work. I looked at the XML of the storyboard and I can see that it just adds the colour's name. So this must be a compiler issue?