diff --git a/ammico/colors.py b/ammico/colors.py
index 0605a24d..43cdb0c5 100644
--- a/ammico/colors.py
+++ b/ammico/colors.py
@@ -91,7 +91,12 @@ def analyse_image(self):
                 merge_color=self.merge_color,
                 delta_e_method=self.delta_e_method,
             )
-            self.subdict[rgb_name] += round(color.proportion, 2)
+            self.subdict[rgb_name] += color.proportion
+
+        # ensure color rounding
+        for key in self.set_keys().keys():
+            if self.subdict[key]:
+                self.subdict[key] = round(self.subdict[key], 2)
 
         return self.subdict
 
diff --git a/ammico/test/test_colors.py b/ammico/test/test_colors.py
index 05fef3b2..8d8f2de9 100644
--- a/ammico/test/test_colors.py
+++ b/ammico/test/test_colors.py
@@ -1,5 +1,6 @@
 from ammico.colors import ColorDetector
 import pytest
+from numpy import isclose
 
 
 def test_init():
@@ -57,11 +58,20 @@ def test_analyze_images(get_path):
     mydict_1 = {
         "filename": get_path + "IMG_2809.png",
     }
+    mydict_2 = {
+        "filename": get_path + "IMG_2809.png",
+    }
 
     test1 = ColorDetector(mydict_1, delta_e_method="CIE 2000").analyse_image()
-    assert test1["red"] == 0.0
-    assert round(test1["green"], 2) == 0.62
+    assert isclose(test1["red"], 0.0, atol=0.01)
+    assert isclose(test1["green"], 0.63, atol=0.01)
+
+    test2 = ColorDetector(mydict_2).analyse_image()
+    assert isclose(test2["red"], 0.0, atol=0.01)
+    assert isclose(test2["green"], 0.06, atol=0.01)
 
-    test2 = ColorDetector(mydict_1).analyse_image()
-    assert test2["red"] == 0.0
-    assert test2["green"] == 0.05
+    mydict_1["test"] = "test"
+    test3 = ColorDetector(mydict_1).analyse_image()
+    assert isclose(test3["red"], 0.0, atol=0.01)
+    assert isclose(test3["green"], 0.06, atol=0.01)
+    assert test3["test"] == "test"