What's the right ';Avon-Mark'; powder buff foundation color for me?

In Mac's studio fix, my color is NW25 and I don't know what that's comparable to in the Mark Powder Buff Natural Skin Foundation. Help!








Here's the link to the colors of Mark's Powder Buff:


http://shop.avon.com/shop/product.aspx?src_page=product_list.aspx%26amp;level1_id=300%26amp;level2_id=469%26amp;pdept_id=483%26amp;dept_id=490%26amp;pf_id=30488What's the right ';Avon-Mark'; powder buff foundation color for me?
The Mark Powder Buff foundation in neutral appears to be a comparable shade.


http://www.youravon.com/kwatts3417