diff --git a/plotter.py b/plotter.py
index ea0893f..aef79e2 100644
--- a/plotter.py
+++ b/plotter.py
@@ -479,7 +479,9 @@ class Plotter(Aggregator, BaseProcessor):
 
         P.clabel(cont, cont.levels[cont.levels < 11], inline=1, fontsize=8.0, fmt="%1d")
 
-    def _overlay_speed(self, ax_los, unit=cst.km_s, unit_coeff=1.0, key_v=None):
+    def _overlay_speed(
+        self, ax_los, unit=cst.km_s, unit_coeff=1.0, key_v=None, **kwargs
+    ):
         ax_h = self._axes_h[ax_los]
         ax_v = self._axes_v[ax_los]
         dmap_vh_node = self.save.get_node("/maps/speed_h_{}".format(ax_los))
@@ -506,7 +508,7 @@ class Plotter(Aggregator, BaseProcessor):
         max_v = np.max(norm_v)
         min_v = np.min(norm_v)
 
-        Q = P.quiver(hh, vv, map_vh_red, map_vv_red, units="width", color="grey")
+        Q = P.quiver(hh, vv, map_vh_red, map_vv_red, units="width", **kwargs)
         label, unit_old, unit = self._ax_label_unit(dmap_vh_node, "", unit, unit_coeff)
 
         if key_v is None:
@@ -521,7 +523,7 @@ class Plotter(Aggregator, BaseProcessor):
             coordinates="figure",
         )
 
-    def _overlay_B(self, ax_los):
+    def _overlay_B(self, ax_los, **kwargs):
         ax_h = self._axes_h[ax_los]
         ax_v = self._axes_v[ax_los]
         dmap_Bh_node = self.save.get_node("/maps/B_h_{}".format(ax_los))
@@ -545,6 +547,8 @@ class Plotter(Aggregator, BaseProcessor):
         ) * lbox
         hh, vv = np.meshgrid(vec_h, vec_v)
 
+        P.streamplot(hh, vv, map_Bh_red, map_Bv_red, **kwargs)
+
         P.streamplot(hh, vv, map_Bh_red, map_Bv_red)
 
     def _plot_radial(self, name, ax_los, label=None, xlog=False, ylog=False):