We study the behavior of the signature of colored links [Flo05, CF08] under
the splice operation. We extend the construction to colored links in integral
homology spheres and show that the signature is almost additive, with a
correction term independent of the links. We interpret this correction term as
the signature of a generalized Hopf link and give a simple closed formula to
compute it.Comment: Updated version. Sign corrected in Theorems 2.2 and 2.10 of the
previous version. Also Corollary 2.6 was corrected and an Example added. 24
pages, 5 figures. To appear in IMR
