Set default entropy plot background to black and line color to yellow

src/binwalk/modules/entropy.py

@@ -261,15 +261,15 @@ class Entropy(Module):
             y.append(r.entropy)
 
         fig = plt.figure()
-        ax = fig.add_subplot(1, 1, 1, autoscale_on=True)
+        ax = fig.add_subplot(1, 1, 1, autoscale_on=True, axisbg='black')
         ax.set_title(fname)
         ax.set_xlabel(self.XLABEL)
         ax.set_ylabel(self.YLABEL)
-        ax.plot(x, y, lw=2)
+        ax.plot(x, y, 'y', lw=2)
 
         # Add a fake, invisible plot entry so that offsets at/near the
         # minimum x value (0) are actually visible on the plot.
-        ax.plot(-(max(x)*.001), 0, lw=0)
+        ax.plot(-(max(x)*.001), 1.1, lw=0)
 
         if self.show_legend and has_key(self.file_markers, fname):
             for (offset, description) in self.file_markers[fname]: