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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`ax.set_prop_cycle` does not allow 'CN' colors","articleBody":"Hi matplotlib developers,\r\nI was surprised to discover that the cycler validation does not allow colors specified with `'CN'` syntax.\r\n\r\n```python\r\nimport numpy as np\r\nimport matplotlib.pyplot as plt\r\nfrom cycler import cycler\r\n\r\nfig, ax = plt.subplots()\r\nax.set_prop_cycle(cycler(color=['C1', 'C0'])) # raises ValueError\r\n# ax.set_prop_cycle(cycler(color=['tab:orange', 'tab:blue'])) # works fine\r\nax.plot(np.arange(9))\r\nax.plot(-np.arange(9))\r\nplt.show()\r\n```\r\nIf matplotlib can differentiate between `{'C0', 'C1', 'C2', 'C3', 'C4', 'C5', 'C6', 'C7', 'C8', 'C9'}` colors and `{'b', 'g', 'r', 'c', 'm', 'y', 'k', 'w'}` colors (case insensitive) anywhere else that a color is specified, then it seems to me that the cycler should be able to handle this as well. Thanks.\r\n\r\nTested with matplotlib 3.0.3 and python 3.7.3 (Anaconda) on Windows 10.\r\n","author":{"url":"https://github.com/u55","@type":"Person","name":"u55"},"datePublished":"2019-05-14T17:13:48.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":15},"url":"https://github.com/14221/matplotlib/issues/14221"}