5 confoederatio Helvetica 1985,

Is this alloy variation/wrong metal error cause it's look more in gold colour than others 5 confoederatio Helvetica I have

Up until 1980 the 5 rappen was a copper nickel coin : N#168

From 1981 onwards it is aluminium bronze, so gold coloured: N#171

Again, please check the catalogue before posting about “unusual” coins.

I don't know to use catalogue 

Best to start here then: https://en.numista.com/help/how-can-i-search-the-catalogue-99.html

Unjucoins

I don't know to use catalogue 

But you do know three things about this coin. You listed them in your title.

1. Helvetica (Switzerland)

2. 5

3. 1985

Use them in a search:

https://en.numista.com/catalogue/index.php?e=suisse&r=&st=1-2-3&cat=y&im1=&im2=&ru=&ie=&ca=3&no=&v=5&a=&dg=1985&i=&b=&m=&f=&t=&t2=&w=&mt=&u=&g=&c=&wi=&sw=