Change pie chart colors before saving plot image to png

[OAHLSTM]

Hello,
I'm trying to plot an pie chart while customizing the colors of its 3 parts. But I'm unable to change the colors while saving the figure. I have tried with colors as vector, a vector of HEX color values and as vector_2d, here is my code:

auto f = matplot::gcf(true);
std::vector<std::string> test_colors = {"#03234B", "#425A78", "#FFD200"};
std::vector<std::string> testcolors = {"red", "magenta", "blue"};
matplot::vector_2d newcolors = {{0.83, 0.14, 0.14},
                         {1.00, 0.54, 0.00},
                         {0.47, 0.25, 0.80},
                         {0.25, 0.80, 0.54}};
std::vector<double> explode = {1, 1, 1};
matplot::colororder(test_colors);
auto p = matplot::pie(data_vector, explode, text_vector);
f->custom_color(1);
f->save(chart_path.c_str());

Any help might be appreciated ? thank you so much in advance.

[nlogozzo]

+1