add a dominance threshold for colour handling

bus_service.py

@@ -199,6 +199,11 @@ def _get_dithering_colors(self, target_rgb: Tuple[int, int, int]) -> Tuple[str,
         # Ensure ratio is between 0.0 and 1.0
         ratio = max(0.0, min(1.0, ratio))
 
+        # If the primary color is very dominant (>80%), use it exclusively
+        DOMINANCE_THRESHOLD = 0.8
+        if ratio >= DOMINANCE_THRESHOLD:
+            return color1, color2, 1.0
+
         return color1, color2, ratio
 
     def set_epd(self, epd):

color_utils.py

@@ -17,6 +17,17 @@ def find_optimal_colors(pixel_rgb, epd):
     yellow_ratio = min(r, g) / 255.0  # Yellow needs both red and green
     orange_factor = min(r, g) / max(1, r) if r > 0 else 0  # How "yellow" is the orange
 
+    # Check for dominant colors first
+    DOMINANCE_THRESHOLD = 0.8
+    if has_yellow and r > 200 and g > 200 and b < 100:  # Strong yellow
+        yellow_strength = min(r, g) / 255.0
+        if yellow_strength >= DOMINANCE_THRESHOLD:
+            return [('yellow', 1.0)]
+    if has_red and r > 200 and g < 100 and b < 100:  # Strong red
+        red_strength = r / 255.0
+        if red_strength >= DOMINANCE_THRESHOLD:
+            return [('red', 1.0)]
+
     # Handle pure white specially
     if r > 250 and g > 250 and b > 250:
         return [('white', 1.0)]