diff --git a/cssutils/css/value.py b/cssutils/css/value.py
index fc69d61c..438b0f2b 100644
--- a/cssutils/css/value.py
+++ b/cssutils/css/value.py
@@ -314,7 +314,6 @@ class ColorValue(Value):
 
     from .colors import COLORS
 
-    type = Value.COLOR_VALUE
     # hexcolor, FUNCTION?
     _colorType = None
     _red = 0
diff --git a/cssutils/tests/test_cssstyledeclaration.py b/cssutils/tests/test_cssstyledeclaration.py
index 4860f4f6..aa9c3f08 100644
--- a/cssutils/tests/test_cssstyledeclaration.py
+++ b/cssutils/tests/test_cssstyledeclaration.py
@@ -81,9 +81,7 @@ def test__iter__item(self):
             border: 0;
         '''
         # __iter__
-        ps = []
-        for p in s:
-            ps.append((p.literalname, p.value, p.priority))
+        ps = [(p.literalname, p.value, p.priority) for p in s]
         assert len(ps) == 3
         assert ps[0] == (r'co\lor', 'green', '')
         assert ps[1] == (r'left', '1px', 'important')
@@ -184,7 +182,7 @@ def test_children(self):
 
         def t(s):
             for i, x in enumerate(s.children()):
-                assert types[i] == type(x)
+                assert isinstance(x, types[i])
                 assert x.parent == s
 
         t(cssutils.parseStyle(style))
diff --git a/cssutils/tests/test_cssvalue.py b/cssutils/tests/test_cssvalue.py
index 5dbb0c5a..1b527d6c 100644
--- a/cssutils/tests/test_cssvalue.py
+++ b/cssutils/tests/test_cssvalue.py
@@ -331,7 +331,7 @@ def test_cssValueType(self):
                 assert value == v.cssText
                 assert name == v.cssValueTypeString
                 assert getattr(v, name) == v.cssValueType
-                assert cls == type(v)
+                assert isinstance(v, cls)
 
     def test_readonly(self):
         "(CSSValue._readonly)"
@@ -636,7 +636,7 @@ def test_setFloat(self):
             initialType, initialValue = test
             pv = cssutils.css.CSSPrimitiveValue(initialValue)
             for setType, setValue, exp, cssText in tests[test]:
-                if type(exp) == type or type(exp) == type:  # 2.4 compatibility
+                if isinstance(exp, type):
                     if cssText:
                         with pytest.raises(exp, match=cssText):
                             pv.setFloatValue(setType, setValue)
diff --git a/cssutils/tests/test_cssvariablesdeclaration.py b/cssutils/tests/test_cssvariablesdeclaration.py
index 826f25c1..e1d91957 100644
--- a/cssutils/tests/test_cssvariablesdeclaration.py
+++ b/cssutils/tests/test_cssvariablesdeclaration.py
@@ -64,10 +64,8 @@ def test_items(self):
         assert 0 == v.length
 
         v.cssText = 'x:0; y:1'
-        keys = []
         # unsorted!
-        for i in range(0, v.length):
-            keys.append(v.item(i))
+        keys = [v.item(i) for i in range(0, v.length)]
         assert sorted(keys) == ['x', 'y']
 
     def test_keys(self):
diff --git a/cssutils/tests/test_value.py b/cssutils/tests/test_value.py
index 6cd0c999..a808881c 100644
--- a/cssutils/tests/test_value.py
+++ b/cssutils/tests/test_value.py
@@ -776,7 +776,7 @@ def test_cssValueType(self):
                 assert value == v.cssText
                 assert name == v.cssValueTypeString
                 assert getattr(v, name) == v.cssValueType
-                assert cls == type(v)
+                assert isinstance(v, cls)
 
 
 @pytest.mark.xfail(reason="not implemented")