There is an older post about interior color amd the use of sem palomino #15323. I bought some and painted my rear hatch caps. Needless to say its not even close. So in closing it might be "close" but not close enough for me...
I will have to look again, but there is a good write up from several years ago on the GTA source page. I tried looking a couple of years ago when I was redoing my 89 GTA and I seem to think it was a special order color and you had to find someone locally that would mix it.
It is funny, but it could be both colors since the majority of TTA's I see at shows have different color panels in their cars. I see many cars with light and darker Camel pieces, especially the ones that cover the rear shoulder harnesses. I think I like the darker better. So maybe the 15173 is correct. I never sprayed my 15323 on anything. :/
Just a heads-up: I went to the Fiero Store's site this morning to order some of their Beechwood interior paint/dye and it's no longer listed as an option. So, I just called their customer service line to see what was up and they said that they're completely out of that color and will no longer sell ANY interior paint/dyes of any color once what they have in stock is depleted.