  Several classical knot invariants, such as the Alexander polynomial, the
Levine-Tristram signature and the Blanchfield pairing, admit natural extensions
from knots to links, and more generally, from oriented links to so-called
colored links. In this note, we explore such extensions of the Arf invariant.
Inspired by the three examples stated above, we use generalized Seifert forms
to construct quadratic forms, and determine when the Arf invariant of such a
form yields a well-defined invariant of colored links. However, apart from the
known case of oriented links, these new Arf invariants turn out to be
determined by the linking numbers.
