How to preserve colors in histogram2

Hello all,

i try to plot 5 datasets using histogram2 and hold on. I realize that the colors are not preserved (colors not showing correctly the number of points, see below for a better explanation). It looks like an overlapping issue.

Below is the piece of cde used in a loop to plot all 5 datasets.

for i2=1:5
 
lonf = data(:,i2);
latf = data1(:,i2);
 
    subplot(ax2), histogram2(lonf,latf,'BinWidth',[10 5],'FaceColor',nco(i2,:),...
        'EdgeColor',nco(i2,:));hold(ax2,'on')
 
end

where: nco=new color order from matlab and

latf and lonf are read each time in the loop

In the attached figure, you see the edges which delimitate different datasets. For example, there is a blue edge in the green bar. The color below the blue edge should have been blue, etc but it's green. I would appreciate any help for solving this issue.

Thank you in advance

Kostas