diff --git a/src/llmtuner/extras/ploting.py b/src/llmtuner/extras/ploting.py
index 462392f5..74d7358c 100644
--- a/src/llmtuner/extras/ploting.py
+++ b/src/llmtuner/extras/ploting.py
@@ -46,8 +46,8 @@ def plot_loss(save_dictionary: os.PathLike, keys: Optional[List[str]] = ["loss"]
             continue
 
         plt.figure()
-        plt.plot(steps, metrics, alpha=0.4, label="original")
-        plt.plot(steps, smooth(metrics), label="smoothed")
+        plt.plot(steps, metrics, color="#1f77b4", alpha=0.4, label="original")
+        plt.plot(steps, smooth(metrics), color="#1f77b4", label="smoothed")
         plt.title("training {} of {}".format(key, save_dictionary))
         plt.xlabel("step")
         plt.ylabel(key)
diff --git a/src/llmtuner/webui/utils.py b/src/llmtuner/webui/utils.py
index 55a4865b..05cdd7f6 100644
--- a/src/llmtuner/webui/utils.py
+++ b/src/llmtuner/webui/utils.py
@@ -82,6 +82,7 @@ def gen_plot(base_model: str, finetuning_type: str, output_dir: str) -> "matplot
         return
 
     plt.close("all")
+    plt.switch_backend("agg")
     fig = plt.figure()
     ax = fig.add_subplot(111)
     steps, losses = [], []
@@ -95,8 +96,8 @@ def gen_plot(base_model: str, finetuning_type: str, output_dir: str) -> "matplot
     if len(losses) == 0:
         return None
 
-    ax.plot(steps, losses, alpha=0.4, label="original")
-    ax.plot(steps, smooth(losses), label="smoothed")
+    ax.plot(steps, losses, color="#1f77b4", alpha=0.4, label="original")
+    ax.plot(steps, smooth(losses), color="#1f77b4", label="smoothed")
     ax.legend()
     ax.set_xlabel("step")
     ax.set_ylabel("loss")