There are two ways to print a Stateflow chart without the beige background color.
Option 1, From the Stateflow UI
1. Select the "Edit" -> "Style" menu.
2. Click on the background of the example chart that will appear.
3. Choose white (or whatever color you want), and click OK to dismiss the color picker.
4. Click apply and the chart will turn white.
5. Now, you can print without the beige background.
Option 2, From the Stateflow API
First, get a handle to the chart. The following code will work for the simple case of one chart open, see Stateflow API documentation for full details.
myChart = find(sf, '-isa', 'Stateflow.Chart');
oldColor = get(myChart, 'ChartColor');
set(myChart, 'ChartColor', [1 1 1]); % RGB values for white
%%Now, print the chart
shh = get(0,'ShowHiddenHandles');
set(0,'ShowHiddenHandles','on');
open_system(myChart.Path)
print(gcf)
%%reset original state
close_system(myChart.Path)
set(0,'ShowHiddenHandles',shh);
set(myChart, 'ChartColor', oldColor);
