Fixed line color issue (ensured valid HEX format)

app.py

@@ -6,11 +6,12 @@ import os  # For handling file paths
 
 def plot_function(func_str, x_min, x_max, resolution, color, linestyle, grid):
     try:
-        # Ensure a valid color (default to black if None or invalid)
+        # Ensure the color is always a valid HEX string
         if not color or not color.startswith("#") or len(color) != 7:
             color = "#000000"  # Default to black
 
-        rgba_color = mcolors.to_rgba(color)  # Convert HEX to RGBA
+        # Convert to proper HEX format for Matplotlib
+        color = mcolors.to_hex(color)  
 
         x_values = np.linspace(x_min, x_max, resolution)
         functions = func_str.split(",")
@@ -21,7 +22,7 @@ def plot_function(func_str, x_min, x_max, resolution, color, linestyle, grid):
             func_text = func_text.strip()
             func = lambda x: eval(func_text, {"x": x, "np": np})
             y_values = func(x_values)
-            plt.plot(x_values, y_values, label=f"f(x) = {func_text}", color=rgba_color, linestyle=linestyle)
+            plt.plot(x_values, y_values, label=f"f(x) = {func_text}", color=color, linestyle=linestyle)
 
         plt.xlabel("x")
         plt.ylabel("f(x)")