diff --git a/release/datafiles/userdef/userdef_default_theme.c b/release/datafiles/userdef/userdef_default_theme.c
index 69e06e25bd7..14c1b9d2a94 100644
--- a/release/datafiles/userdef/userdef_default_theme.c
+++ b/release/datafiles/userdef/userdef_default_theme.c
@@ -869,7 +869,7 @@ const bTheme U_theme_default = {
     .nodeclass_layout = RGBA(0x6c696fff),
     .nodeclass_geometry = RGBA(0x00d6a3ff),
     .nodeclass_attribute = RGBA(0x001566ff),
-    .node_zone_simulation = RGBA(0x00000011),
+    .node_zone_simulation = RGBA(0x66416233),
     .movie = RGBA(0x0f0f0fcc),
     .gp_vertex_size = 3,
     .gp_vertex = RGBA(0x97979700),
diff --git a/source/blender/blenloader/intern/versioning_userdef.c b/source/blender/blenloader/intern/versioning_userdef.c
index 399e7b6366b..ea61273ca39 100644
--- a/source/blender/blenloader/intern/versioning_userdef.c
+++ b/source/blender/blenloader/intern/versioning_userdef.c
@@ -108,10 +108,7 @@ static void do_versions_theme(const UserDef *userdef, bTheme *btheme)
    */
   {
     /* Keep this block, even when empty. */
-
-    if (btheme->space_node.node_zone_simulation[3] == 0) {
-      btheme->space_node.node_zone_simulation[3] = 0x11;
-    }
+    FROM_DEFAULT_V4_UCHAR(space_node.node_zone_simulation);
   }
 
 #undef FROM_DEFAULT_V4_UCHAR
diff --git a/source/blender/editors/space_node/node_draw.cc b/source/blender/editors/space_node/node_draw.cc
index ccd48a748a7..63eb4e19c6a 100644
--- a/source/blender/editors/space_node/node_draw.cc
+++ b/source/blender/editors/space_node/node_draw.cc
@@ -3122,6 +3122,7 @@ static void find_bounds_by_zone_recursive(const SpaceNode &snode,
 }
 
 static void node_draw_zones(TreeDrawContext & /*tree_draw_ctx*/,
+                            const ARegion &region,
                             const SpaceNode &snode,
                             const bNodeTree &ntree)
 {
@@ -3131,6 +3132,8 @@ static void node_draw_zones(TreeDrawContext & /*tree_draw_ctx*/,
   }
 
   Array<Vector<float2>> bounds_by_zone(zones->zones.size());
+  Array<bke::CurvesGeometry> fillet_curve_by_zone(zones->zones.size());
+
   for (const int zone_i : zones->zones.index_range()) {
     const TreeZone &zone = *zones->zones[zone_i];
 
@@ -3151,27 +3154,56 @@ static void node_draw_zones(TreeDrawContext & /*tree_draw_ctx*/,
     }
     boundary_curve.tag_topology_changed();
 
-    bke::CurvesGeometry fillet_curve = geometry::fillet_curves_poly(
+    fillet_curve_by_zone[zone_i] = geometry::fillet_curves_poly(
         boundary_curve,
         IndexRange(1),
-        VArray<float>::ForSingle(UI_UNIT_X / 2, boundary_positions_num),
+        VArray<float>::ForSingle(BASIS_RAD, boundary_positions_num),
         VArray<int>::ForSingle(5, boundary_positions_num),
         true,
         {});
-    const Span<float3> fillet_boundary_positions = fillet_curve.positions();
+  }
 
-    const uint pos = GPU_vertformat_attr_add(
-        immVertexFormat(), "pos", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
+  const View2D &v2d = region.v2d;
+  float scale;
+  UI_view2d_scale_get(&v2d, &scale, nullptr);
+  float line_width = 1.0f * scale;
+  float viewport[4] = {};
+  GPU_viewport_size_get_f(viewport);
+  float zone_color[4];
+  UI_GetThemeColor4fv(TH_NODE_ZONE_SIMULATION, zone_color);
+
+  const uint pos = GPU_vertformat_attr_add(
+      immVertexFormat(), "pos", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
+
+  /**
+   * Draw all the countour lines after to prevent them from getting hidden.
+   * Once we support other zones (e.g., for loops) we will need to sort them in a smarter way.
+   */
+  for (const int zone_i : zones->zones.index_range()) {
+    if (zone_color[3] == 0.0f) {
+      break;
+    }
+    const Span<float3> fillet_boundary_positions = fillet_curve_by_zone[zone_i].positions();
+    /* Draw the background. */
     immBindBuiltinProgram(GPU_SHADER_3D_UNIFORM_COLOR);
+    immUniformThemeColorBlend(TH_BACK, TH_NODE_ZONE_SIMULATION, zone_color[3]);
 
-    GPU_blend(GPU_BLEND_ALPHA);
-    immUniformThemeColor(TH_NODE_ZONE_SIMULATION);
     immBegin(GPU_PRIM_TRI_FAN, fillet_boundary_positions.size() + 1);
     for (const float3 &p : fillet_boundary_positions) {
       immVertex3fv(pos, p);
     }
     immVertex3fv(pos, fillet_boundary_positions[0]);
     immEnd();
+  }
+
+  for (const int zone_i : zones->zones.index_range()) {
+    const Span<float3> fillet_boundary_positions = fillet_curve_by_zone[zone_i].positions();
+    /* Draw the countour lines. */
+    immBindBuiltinProgram(GPU_SHADER_3D_POLYLINE_UNIFORM_COLOR);
+
+    immUniform2fv("viewportSize", &viewport[2]);
+    immUniform1f("lineWidth", line_width * U.pixelsize);
+
     immUniformThemeColorAlpha(TH_NODE_ZONE_SIMULATION, 1.0f);
     immBegin(GPU_PRIM_LINE_STRIP, fillet_boundary_positions.size() + 1);
     for (const float3 &p : fillet_boundary_positions) {
@@ -3181,7 +3213,6 @@ static void node_draw_zones(TreeDrawContext & /*tree_draw_ctx*/,
     immEnd();
 
     immUnbindProgram();
-    GPU_blend(GPU_BLEND_NONE);
   }
 }
 
@@ -3352,7 +3383,7 @@ static void draw_nodetree(const bContext &C,
   }
 
   node_update_nodetree(C, tree_draw_ctx, ntree, nodes, blocks);
-  node_draw_zones(tree_draw_ctx, *snode, ntree);
+  node_draw_zones(tree_draw_ctx, region, *snode, ntree);
   node_draw_nodetree(C, tree_draw_ctx, region, *snode, ntree, nodes, blocks, parent_key);
 }
 
diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index 6b6b6eb52ab..e0ebc2f916d 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -3057,7 +3057,7 @@ static void rna_def_userdef_theme_space_node(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Attribute Node", "");
   RNA_def_property_update(prop, 0, "rna_userdef_theme_update");
 
-  prop = RNA_def_property(srna, "simulation_region", PROP_FLOAT, PROP_COLOR_GAMMA);
+  prop = RNA_def_property(srna, "simulation_zone", PROP_FLOAT, PROP_COLOR_GAMMA);
   RNA_def_property_float_sdna(prop, NULL, "node_zone_simulation");
   RNA_def_property_array(prop, 4);
   RNA_def_property_ui_text(prop, "Simulation Zone", "");