simple or double

(*Mathematica 8 start*)Clear[f, k, s, n]
f[x_] := Zeta[x];
n = 6;
Show[Graphics[
  RasterArray[
   Table[Hue[
     Mod[3 Pi/2 +
        Im[(1/(1 -
              Sum[(((-1)^(k - 1)*Binomial[n - 1, k - 1])/
                  f[k/n + sigma + I t - 1/n]), {k, 1, n}]/
               Sum[(((-1)^(k - 1)*Binomial[n - 1, k - 1])/
                  f[k/n + sigma + I t]), {k, 1, n}]) + sigma + I t)],
       2 Pi]/(2 Pi)], {t, -30, 30, .1}, {sigma, -30, 30, .1}]]],
 AspectRatio -> Automatic]
(*Mathematica end*)