diff --git a/reasoning_gym/algorithmic/graph_color.py b/reasoning_gym/algorithmic/graph_color.py
index 408a9f43..b555ec59 100644
--- a/reasoning_gym/algorithmic/graph_color.py
+++ b/reasoning_gym/algorithmic/graph_color.py
@@ -197,6 +197,9 @@ class GraphColorDataset(ProceduralDataset):
                 num_colors=num_colors,
             )
             solution = greedy_graph_coloring(puzzle)
+            if not solution:
+                num_vertices = rng.randint(self.config.min_num_vertices, self.config.max_num_vertices)
+                num_colors = rng.randint(self.config.min_num_colors, self.config.max_num_colors)
 
         edges = str(puzzle["edges"])
         question = f"""Please provide a coloring for this graph such that every vertex is not connected to a vertex of the same color. The graph has these properties:
@@ -253,21 +256,21 @@ class GraphColorCurriculum(BaseCurriculum):
         self._define_attributes(
             RangeAttributeDefinition(
                 name="num_vertices",
-                levels=[10, 20, 30, 40],
+                levels=[10, 12, 15, 18],
                 default_level=0,
                 description="Number of vertices in the graph",
-                attr_type=AttributeType.APPEND,
+                attr_type=AttributeType.STATIC,
                 min_value=10,
                 lower_field_name="min_num_vertices",
                 upper_field_name="max_num_vertices",
             ),
             RangeAttributeDefinition(
                 name="num_colors",
-                levels=[3, 4, 5, 6],
+                levels=[5, 4, 3],
                 default_level=0,
                 description="Number of colors in the graph",
-                attr_type=AttributeType.APPEND,
-                min_value=2,
+                attr_type=AttributeType.STATIC,
+                min_value=3,
                 lower_field_name="min_num_colors",
                 upper_field_name="max_num_colors",
             ),