Creating a font that has only the inline

I want to offer a version of my font that has only the inline part. That way, the customer can easily recolor only the inline bit if they so choose. So, what I did was to just delete the outer shape while in Glyphsapp. However, when i do that, the metrics become invalid. and they need to be identical for the inline version to be useful. Is this happening because i have used- in this case - the metrics form a different capital letter? How can I make this work correctly??
Thanks

It may be that once you delete the outer layer of the referenced glyph (H in this case) all will be well again.

I’d consider setting this up with the built-in multi-layered color font support. Tutorial is here: https://glyphsapp.com/tutorials/creating-a-layered-color-font

You just don’t update metrics after deleting the path, ignoring the red warnings.

But better probably to remove the references, just so as to avoid accidental updating later. Just highlighting and deleting the reference in the sidebearing box will keep the current metrics and remove the link.

Great. Thanks everyone