fixes bug when plotting multivariate probabilistic series where the c… (

#2532)

* fixes bug when plotting multivariate probabilistic series where the confidence intervals had the same color as central series

* add labels back

* update changelog

CHANGELOG.md

@@ -24,6 +24,7 @@ but cannot always guarantee backwards compatibility. Changes that may **break co
 
 **Fixed**
 
+- Fixed bug when plotting a probabilistic multivariate series, where all confidence intervals (starting from 2nd component) had the same color as the median line. [#2532](https://github.com/unit8co/darts/pull/2532) by [Dennis Bader](https://github.com/dennisbader).
 - Fixed a bug when passing an empty array to `TimeSeries.prepend/append_values()` raised an error. [#2522](https://github.com/unit8co/darts/pull/2522) by [Alessio Pellegrini](https://github.com/AlessiopSymplectic)
 - Fixed a bug with `TimeSeries.prepend/append_values()`, where the name of the (time) index was lost. [#2522](https://github.com/unit8co/darts/pull/2522) by [Alessio Pellegrini](https://github.com/AlessiopSymplectic)
 - Fixed a bug when using `from_group_dataframe()` with a `time_col` of type integer, where the resulting time index was wrongly converted to a DatetimeIndex. [#2512](https://github.com/unit8co/darts/pull/2512) by [Alessio Pellegrini](https://github.com/AlessiopSymplectic)

darts/timeseries.py

@@ -4191,8 +4191,6 @@ def plot(
                 central_series = comp.mean(dim=DIMS[2])
 
             alpha = kwargs["alpha"] if "alpha" in kwargs else None
-            if not self.is_deterministic:
-                kwargs["alpha"] = 1
             if custom_labels:
                 label_to_use = label[i]
             else:
@@ -4204,15 +4202,18 @@ def plot(
                     label_to_use = f"{label}_{comp_name}"
             kwargs["label"] = label_to_use
 
+            kwargs_central = deepcopy(kwargs)
+            if not self.is_deterministic:
+                kwargs_central["alpha"] = 1
             if central_series.shape[0] > 1:
-                p = central_series.plot(*args, ax=ax, **kwargs)
+                p = central_series.plot(*args, ax=ax, **kwargs_central)
             # empty TimeSeries
             elif central_series.shape[0] == 0:
                 p = ax.plot(
                     [],
                     [],
                     *args,
-                    **kwargs,
+                    **kwargs_central,
                 )
                 ax.set_xlabel(self.time_index.name)
             else:
@@ -4221,7 +4222,7 @@ def plot(
                     central_series.values[0],
                     "o",
                     *args,
-                    **kwargs,
+                    **kwargs_central,
                 )
             color_used = p[0].get_color() if default_formatting else None