All parameters how to plot one indicator should be just one style parameter as list of dictionaries, one for each element of the indicator. Then you can specify for MACD to have 2 line elements and one histogram with the corresponding colors and names.

I did some experiments and added a complex style parameter where the user can select even size, transparency, type, color, name etc. of each element of one indicator but it needs much more work before proposing this option. Something like this:

@AGG2017 how did you specify the legends for each of the lines in 1 indicator graph? Could you share the code for this? I'm trying to draw MACD signal like this too. Thanks.

I ended up implement everything my own. Thanks @vladimircape

Hi @vladimircape,

Your tutorial is great. I did it but still cannot generate a histogram with different colors for positive and negative ones.

For now, the histogram has only one color:

Do you know how to generate a histogram with multiple colors as @AGG2017 did? Thank you.

I did it successfully, thanks to everyone under this issue for their help.

@quanvnd9 As for the histogram color, you can use:

cm = linear_cmap(source_name, [lightness(BEAR_COLOR, .6), lightness(BULL_COLOR, .6)], low=0, high=0)
r = fig.vbar('index', BAR_WIDTH, source_name, source=source, legend_label=LegendStr(legend_label), color=cm)

For details, please refer to my fork repository https://github.com/kxbin/backtesting.py