Update link to IBM's colormap selection paper

saketkc · web-flow · commit ea9ecf4b3529 · 2018-07-30T10:32:37.000+05:30
http://www.research.ibm.com/people/l/lloydt/color/color.HTM appears to be not relevant anymore.
diff --git a/tutorials/colors/colormaps.py b/tutorials/colors/colormaps.py
@@ -417,4 +417,4 @@ def plot_color_gradients(cmap_category, cmap_list):
 # .. [bw] http://www.tannerhelland.com/3643/grayscale-image-algorithm-vb6/
 # .. [colorblindness] http://www.color-blindness.com/
 # .. [vischeck] http://www.vischeck.com/vischeck/
-# .. [IBM] http://www.research.ibm.com/people/l/lloydt/color/color.HTM
+# .. [IBM] https://archive.is/fmYgZ
