Large dataset legend for two colours

I am trying to plot eeg data of 6 channels. Three channels are within the same area and other three channels are from another area. So I differentiate them with two colours. However, as I have 6 lines in overall I am able to display only a legend for 6 lines - 3 blue, 3 red, and not legend for 2 colours - blue for one area, red for the other one.

How can I change the legend so I would have only 2 descriptions - one for blue and one for red, please??

figure()
plot(tdata(startsample:endsample)-0.033,eegdata1(:,startsample:endsample),...
    'Color','b');
xlim([-0.08, 0.20])
xlabel('Time')
ylabel('Field')

hold on
plot(tdata(startsample:endsample)-0.033,eegdata2(:,startsample:endsample),...
     '--','Color','r');
 

Answer 1

[darova]

You can use hadlers

h1 = plot()
hold on
h2 = plot()
hold off
legend(h1,'legend red')
legend(h2,'legend blue')

[M03]

It doesn't work. I get legend only for the blue color

[darova]

Can you please attach the data?