Color each boxplot differently

I found an example that allows you to color with random colors. However, I want to color the inside of each boxplot with a certain color.

a = magic(3);
boxplot(a)
i = 3;  % number of boxplots
x = 1:i;
colors = rand(i, 3);
figure
boxplot(a, x,'Whisker', inf);

h = findobj(gca,'Tag','Box');
for j=1:length(h)
    patch(get(h(j),'XData'),get(h(j),'YData'),colors(j,:),'FaceAlpha',.5);
end

I would also like to make the lines thicker. How can I do this?

Answer 1

[Jon]

I think this should get you closer to what you want. You can select other colors using their rgb color codes, I just used red,green and blue in the example

a = magic(3);
boxplot(a)
i = 3;  % number of boxplots
x = 1:i;
colors = [1 0 0;0 1 0;0 0 1];
figure
boxplot(a, x,'BoxStyle','outline','Colors',colors);
h = findobj(gca,'Tag','Box');
for j=1:length(h)
    patch(get(h(j),'XData'),get(h(j),'YData'),get(h(j),'Color'),'FaceAlpha',.5);
end

[Jon]

You can also change the linewidth as follows

a = magic(3);
boxplot(a)
i = 3;  % number of boxplots
x = 1:i;
colors = [1 0 0;0 1 0;0 0 1];
lineWidth = 2;
figure
boxplot(a, x,'BoxStyle','outline','Colors',colors)
h = findobj(gca,'Tag','Box');
for j=1:length(h)
    set(h(j),'LineWidth',lineWidth)
    patch(get(h(j),'XData'),get(h(j),'YData'),get(h(j),'Color'),'FaceAlpha',.5);
end

[Alberto Acri]

I was interested in having an increase in the thickness of all the lines in the figure. See below:

[Jon]

If you are running R2020A or higher you may want to investigate boxchart. It seems to offer the options you want more directly