DOC: Document that bar() errorbars do not support individual coloring (matplotlib#31579)

* DOC: Document that bar() errorbars do not support individual coloring

Closes matplotlib#14480.

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Co-authored-by: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>

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Author: timhoffm

lib/matplotlib/axes/_axes.py

@@ -2410,11 +2410,16 @@ def bar(self, x, height, width=0.8, bottom=None, *, align="center",
               errors.
             - *None*: No errorbar. (Default)
 
-            See :doc:`/gallery/statistics/errorbar_features` for an example on
+            This is a convenience shortcut for an extra `~.axes.Axes.errorbar`
+            call. See its documentation and
+            :doc:`/gallery/statistics/errorbar_features` for an example on
             the usage of *xerr* and *yerr*.
 
         ecolor : :mpltype:`color` or list of :mpltype:`color`, default: 'black'
             The line color of the errorbars.
+            Multiple colors are only supported if the errorbars do not have
+            caps. If you need individually colored errorbars with caps, instead
+            use explicit `~.axes.Axes.errorbar` calls for each data point.
 
         capsize : float, default: :rc:`errorbar.capsize`
            The length of the error bar caps in points.