Advice on correctly adding metal composition

I am trying to add a gold £2 coin and the Royal Mint states it has Inner: 22 carat yellow gold. Outer: 22 carat red gold. So, 2 questions is this technically 2 metals? and if so would I select bimetallic? If so this is how i would think to add it:


However it looks like this:

But this looks very messy

In my mind there needs to be an additional details field for each part of the bimetallic element.

I looked at the guidelines and couldn't see anything relating to this. So any advice on how to correctly add would be welcome of there is a convention.

It's going to be messy even with additional detail fields. The only was I see (keep in mind I'm not that creative) is to add additional choices for gold (e.g. red, yellow, pink, white). I think you'll either need to live with messy or just put the types in the comment section.

Hello,
This is a quite specific case, so I don't think we should change the composition field for that.
The way you entered the composition looks god to me.

unfortunately this is not an isolated case with regards to British £2, as all are this composition. but if you are happy i am happy