BUG: Fix iterable color= param for non-overlay indicators

backtesting/_plotting.py

@@ -25,8 +25,7 @@ from bokeh.layouts import gridplot
 from bokeh.palettes import Category10
 from bokeh.transform import factor_cmap
 
-from backtesting._util import _data_period
-
+from backtesting._util import _data_period, _as_list
 
 IS_JUPYTER_NOTEBOOK = 'JPY_PARENT_PID' in os.environ
 
@@ -425,12 +424,12 @@ return this.labels[index] || "";
             if not value._opts.get('plot') or _too_many_dims(value):
                 continue
 
-            color = value._opts['color']
             tooltips = []
 
             # Overlay indicators on the OHLC figure
             if value._opts['overlay']:
-                color = color or next(ohlc_colors)
+                color = value._opts['color']
+                color = color and _as_list(color)[0] or next(ohlc_colors)
                 legend = LegendStr(value.name)
                 for i, arr in enumerate(value):
                     source_name = '{}_{}'.format(value.name, i)
@@ -442,7 +441,8 @@ return this.labels[index] || "";
                 ohlc_tooltips.append((value.name, NBSP.join(tooltips)))
             else:
                 # Standalone indicator sections at the bottom
-                color = color or colorgen()
+                color = value._opts['color']
+                color = color and cycle(_as_list(color)) or colorgen()
                 fig = new_indicator_figure()
                 for i, arr in enumerate(value, 1):
                     legend = '{}-{}'.format(value.name, i) if len(value) > 1 else value.name

backtesting/_util.py

@@ -1,4 +1,4 @@
-
+from collections import Sequence
 from numbers import Number
 
 import numpy as np
@@ -18,6 +18,12 @@ def _as_str(value):
     return name
 
 
+def _as_list(value):
+    if isinstance(value, Sequence) and not isinstance(value, str):
+        return list(value)
+    return [value]
+
+
 def _data_period(df):
     """Return data index period as pd.Timedelta"""
     return df.index[:100].to_series().diff().median()

backtesting/test/_test.py

@@ -409,6 +409,22 @@ class TestPlot(TestCase):
             # Give browser time to open before tempfile is removed
             time.sleep(5)
 
+    def test_indicator_color(self):
+        class S(Strategy):
+            def init(self):
+                a = self.I(SMA, self.data.Close, 5, overlay=True, color='red')
+                b = self.I(SMA, self.data.Close, 10, overlay=False, color='blue')
+                self.I(lambda: (a, b), overlay=False, color=('green', 'orange'))
+            def next(self):
+                pass
+
+        bt = Backtest(GOOG, S)
+        bt.run()
+        with _tempfile() as f:
+            bt.plot(filename=f,
+                    plot_drawdown=False, plot_equity=False, plot_pl=False, plot_volume=False,
+                    open_browser=False)
+
 
 class TestLib(TestCase):
     def test_barssince(self):