diff --git a/src/ms3/utils/constants.py b/src/ms3/utils/constants.py
index b3a97655..644fcae2 100644
--- a/src/ms3/utils/constants.py
+++ b/src/ms3/utils/constants.py
@@ -410,7 +410,155 @@
 
 MS3_COLORS = list(MS3_HTML.values())
 CSS2MS3 = {c[4:]: c for c in MS3_COLORS}
-CSS_COLORS = list(webcolors.CSS3_NAMES_TO_HEX.keys())
+CSS_COLORS = [ # copied from webcolors.CSS3_NAMES_TO_HEX.keys()        (<=1.13)
+ 'aliceblue',  #             webcolors._definitions._CSS3_NAMES_TO_HEX (> 1.13)
+ 'antiquewhite',
+ 'aqua',
+ 'aquamarine',
+ 'azure',
+ 'beige',
+ 'bisque',
+ 'black',
+ 'blanchedalmond',
+ 'blue',
+ 'blueviolet',
+ 'brown',
+ 'burlywood',
+ 'cadetblue',
+ 'chartreuse',
+ 'chocolate',
+ 'coral',
+ 'cornflowerblue',
+ 'cornsilk',
+ 'crimson',
+ 'cyan',
+ 'darkblue',
+ 'darkcyan',
+ 'darkgoldenrod',
+ 'darkgray',
+ 'darkgrey',
+ 'darkgreen',
+ 'darkkhaki',
+ 'darkmagenta',
+ 'darkolivegreen',
+ 'darkorange',
+ 'darkorchid',
+ 'darkred',
+ 'darksalmon',
+ 'darkseagreen',
+ 'darkslateblue',
+ 'darkslategray',
+ 'darkslategrey',
+ 'darkturquoise',
+ 'darkviolet',
+ 'deeppink',
+ 'deepskyblue',
+ 'dimgray',
+ 'dimgrey',
+ 'dodgerblue',
+ 'firebrick',
+ 'floralwhite',
+ 'forestgreen',
+ 'fuchsia',
+ 'gainsboro',
+ 'ghostwhite',
+ 'gold',
+ 'goldenrod',
+ 'gray',
+ 'grey',
+ 'green',
+ 'greenyellow',
+ 'honeydew',
+ 'hotpink',
+ 'indianred',
+ 'indigo',
+ 'ivory',
+ 'khaki',
+ 'lavender',
+ 'lavenderblush',
+ 'lawngreen',
+ 'lemonchiffon',
+ 'lightblue',
+ 'lightcoral',
+ 'lightcyan',
+ 'lightgoldenrodyellow',
+ 'lightgray',
+ 'lightgrey',
+ 'lightgreen',
+ 'lightpink',
+ 'lightsalmon',
+ 'lightseagreen',
+ 'lightskyblue',
+ 'lightslategray',
+ 'lightslategrey',
+ 'lightsteelblue',
+ 'lightyellow',
+ 'lime',
+ 'limegreen',
+ 'linen',
+ 'magenta',
+ 'maroon',
+ 'mediumaquamarine',
+ 'mediumblue',
+ 'mediumorchid',
+ 'mediumpurple',
+ 'mediumseagreen',
+ 'mediumslateblue',
+ 'mediumspringgreen',
+ 'mediumturquoise',
+ 'mediumvioletred',
+ 'midnightblue',
+ 'mintcream',
+ 'mistyrose',
+ 'moccasin',
+ 'navajowhite',
+ 'navy',
+ 'oldlace',
+ 'olive',
+ 'olivedrab',
+ 'orange',
+ 'orangered',
+ 'orchid',
+ 'palegoldenrod',
+ 'palegreen',
+ 'paleturquoise',
+ 'palevioletred',
+ 'papayawhip',
+ 'peachpuff',
+ 'peru',
+ 'pink',
+ 'plum',
+ 'powderblue',
+ 'purple',
+ 'red',
+ 'rosybrown',
+ 'royalblue',
+ 'saddlebrown',
+ 'salmon',
+ 'sandybrown',
+ 'seagreen',
+ 'seashell',
+ 'sienna',
+ 'silver',
+ 'skyblue',
+ 'slateblue',
+ 'slategray',
+ 'slategrey',
+ 'snow',
+ 'springgreen',
+ 'steelblue',
+ 'tan',
+ 'teal',
+ 'thistle',
+ 'tomato',
+ 'turquoise',
+ 'violet',
+ 'wheat',
+ 'white',
+ 'whitesmoke',
+ 'yellow',
+ 'yellowgreen'
+]
 COLORS = sum([[c, CSS2MS3[c]] if c in CSS2MS3 else [c] for c in CSS_COLORS], [])
 rgba = namedtuple("RGBA", ["r", "g", "b", "a"])
 DEFAULT_CREATOR_METADATA = {