diff --git a/prody/dynamics/plotting.py b/prody/dynamics/plotting.py
index 364f207d7..83dc9308b 100644
--- a/prody/dynamics/plotting.py
+++ b/prody/dynamics/plotting.py
@@ -271,6 +271,8 @@ def showProjection(ensemble=None, modes=None, projection=None, *args, **kwargs):
         weights = kwargs.pop('weights', None)
         weights = None
 
+    markersize = kwargs.pop('markersize', None)
+
     num = projection.shape[0]
 
     use_labels = kwargs.pop('use_labels', True)
@@ -283,8 +285,14 @@ def showProjection(ensemble=None, modes=None, projection=None, *args, **kwargs):
             labels = modes.getModel()._labels.tolist()
             LOGGER.info('using labels from LDA model')
 
-    if labels is not None and len(labels) != num:
-        raise ValueError('label should have the same length as ensemble')
+    one_label = False
+    if labels is not None:
+        if len(labels) == 1:
+            one_label = True
+            kwargs['label'] = labels
+
+        elif len(labels) != num:
+            raise ValueError('label should have the same length as ensemble')
 
     c = kwargs.pop('c', 'b')
     colors = kwargs.pop('color', c)
@@ -297,14 +305,14 @@ def showProjection(ensemble=None, modes=None, projection=None, *args, **kwargs):
         if len(colors) != num:
             raise ValueError('length of color must be {0}'.format(num))
     elif isinstance(colors, dict):
-        if labels is None:
+        if labels is None or one_label:
             raise TypeError('color must be a string or a list unless labels are provided')
         colors_dict = colors
         colors = [colors_dict[label] for label in labels]
     else:
         raise TypeError('color must be a string or a list or a dict if labels are provided')
 
-    if labels is not None and len(colors_dict) == 0:
+    if labels is not None and not one_label and len(colors_dict) == 0:
         cycle_colors = plt.rcParams['axes.prop_cycle'].by_key()['color']
         for i, label in enumerate(set(labels)):
             colors_dict[label] = cycle_colors[i % len(cycle_colors)]
@@ -318,6 +326,8 @@ def showProjection(ensemble=None, modes=None, projection=None, *args, **kwargs):
             show = plt.plot(range(len(projection)), projection.flatten(), *args, **kwargs)
             if use_weights:
                 kwargs['s'] = weights
+            elif markersize is not None:
+                kwargs['s'] = markersize
             if labels is not None and use_labels:
                 for label in set(labels):
                     kwargs['c'] = colors_dict[label]
@@ -444,6 +454,8 @@ def showProjection(ensemble=None, modes=None, projection=None, *args, **kwargs):
             kwargs['c'] = color
             if weights is not None and use_weights:
                 kwargs['s'] = weights
+            elif markersize is not None:
+                kwargs['s'] = markersize
             plot(*(list(projection[indices].T) + args), **kwargs)
         else:
             kwargs['color'] = color